Common Weakness Enumeration

CWE-83

Allowed

Improper Neutralization of Script in Attributes in a Web Page

Abstraction: Variant · Status: Draft

The product does not neutralize or incorrectly neutralizes "javascript:" or other URIs from dangerous attributes within tags, such as onmouseover, onload, onerror, or style.

49 vulnerabilities reference this CWE, most recent first.

GHSA-5JFW-GQ64-Q45F

Vulnerability from github – Published: 2024-11-19 21:07 – Updated: 2025-01-14 16:37
VLAI
Summary
HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through
Details

Impact

The HTML Parser in lxml does not properly handle context-switching for special HTML tags such as <svg>, <math> and <noscript>. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content.

Patches

Users employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue.

Workarounds

As a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability: * remove_tags: Specify tags to remove - their content is moved to their parents' tags. * kill_tags: Specify tags to be removed completely. * allow_tags: Restrict the set of permissible tags, excluding context-switching tags like <svg>, <math> and <noscript>.

References

  • https://github.com/fedora-python/lxml_html_clean/pull/19
  • https://github.com/fedora-python/lxml_html_clean/pull/19/commits/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "lxml-html-clean"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.4.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-52595"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-184",
      "CWE-79",
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-11-19T21:07:59Z",
    "nvd_published_at": "2024-11-19T22:15:21Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nThe HTML Parser in lxml does not properly handle context-switching for special HTML tags such as `\u003csvg\u003e`, `\u003cmath\u003e` and `\u003cnoscript\u003e`. This behavior deviates from how web browsers parse and interpret such tags. Specifically, content in CSS comments is ignored by lxml_html_clean but may be interpreted differently by web browsers, enabling malicious scripts to bypass the cleaning process. This vulnerability could lead to Cross-Site Scripting (XSS) attacks, compromising the security of users relying on lxml_html_clean in default configuration for sanitizing untrusted HTML content.\n\n### Patches\n\nUsers employing the HTML cleaner in a security-sensitive context should upgrade to lxml 0.4.0, which addresses this issue.\n\n### Workarounds\n\nAs a temporary mitigation, users can configure lxml_html_clean with the following settings to prevent the exploitation of this vulnerability:\n* `remove_tags`: Specify tags to remove - their content is moved to their parents\u0027 tags.\n* `kill_tags`: Specify tags to be removed completely.\n* `allow_tags`: Restrict the set of permissible tags, excluding context-switching tags like `\u003csvg\u003e`, `\u003cmath\u003e` and `\u003cnoscript\u003e`.\n\n### References\n\n* https://github.com/fedora-python/lxml_html_clean/pull/19\n* https://github.com/fedora-python/lxml_html_clean/pull/19/commits/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808\n",
  "id": "GHSA-5jfw-gq64-q45f",
  "modified": "2025-01-14T16:37:30Z",
  "published": "2024-11-19T21:07:59Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-5jfw-gq64-q45f"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-52595"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fedora-python/lxml_html_clean/pull/19"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fedora-python/lxml_html_clean/commit/c5d816f86eb3707d72a8ecf5f3823e0daa1b3808"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/fedora-python/lxml_html_clean"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/lxml-html-clean/PYSEC-2024-160.yaml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "HTML Cleaner allows crafted scripts in special contexts like svg or math to pass through"
}

GHSA-663W-2XP3-5739

Vulnerability from github – Published: 2023-10-25 21:02 – Updated: 2023-11-01 06:06
VLAI
Summary
org.xwiki.rendering:xwiki-rendering-xml Improper Neutralization of Invalid Characters in Identifiers in Web Pages vulnerability
Details

Impact

The cleaning of attributes during XHTML rendering, introduced in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid attribute names. This can be exploited, e.g., via the link syntax in any content that supports XWiki syntax like comments in XWiki:

[[Link1>>https://XWiki.example.com||/onmouseover="alert('XSS1')"]]

When a user moves the mouse over this link, the malicious JavaScript code is executed in the context of the user session. When this user is a privileged user who has programming rights, this allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance.

While this attribute was correctly recognized as not allowed, the attribute was still printed with a prefix data-xwiki-translated-attribute- without further cleaning or validation.

Note that while versions below 14.6 are not vulnerable to this particular vulnerability, they are still vulnerable to XSS through attributes in XWiki syntax, see the corresponding advisory.

Patches

This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by removing characters not allowed in data attributes and then validating the cleaned attribute again.

Workarounds

There are no known workarounds apart from upgrading to a version including the fix.

References

  • https://jira.xwiki.org/browse/XRENDERING-697
  • https://github.com/xwiki/xwiki-rendering/commit/f4d5acac451dccaf276e69f0b49b72221eef5d2f

For more information

If you have any questions or comments about this advisory: * Open an issue in Jira XWiki * Email us at XWiki Security mailing-list

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-xml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "14.6-rc-1"
            },
            {
              "fixed": "14.10.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-37908"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79",
      "CWE-83",
      "CWE-86"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-10-25T21:02:49Z",
    "nvd_published_at": "2023-10-25T18:17:28Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\nThe cleaning of attributes during XHTML rendering, introduced in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid attribute names. This can be exploited, e.g., via the link syntax in any content that supports XWiki syntax like comments in XWiki: \n\n```\n[[Link1\u003e\u003ehttps://XWiki.example.com||/onmouseover=\"alert(\u0027XSS1\u0027)\"]]\n```\n\nWhen a user moves the mouse over this link, the malicious JavaScript code is executed in the context of the user session. When this user is a privileged user who has programming rights, this allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance.\n\nWhile this attribute was correctly recognized as not allowed, the attribute was still printed with a prefix `data-xwiki-translated-attribute-` without further cleaning or validation.\n\nNote that while versions below 14.6 are not vulnerable to this particular vulnerability, they are still vulnerable to XSS through attributes in XWiki syntax, see [the corresponding advisory](https://github.com/xwiki/xwiki-rendering/security/advisories/GHSA-6gf5-c898-7rxp).\n\n### Patches\nThis problem has been patched in XWiki 14.10.4 and 15.0 RC1 by removing characters not allowed in data attributes and then validating the cleaned attribute again.\n\n### Workarounds\nThere are no known workarounds apart from upgrading to a version including the fix.\n\n### References\n* https://jira.xwiki.org/browse/XRENDERING-697\n* https://github.com/xwiki/xwiki-rendering/commit/f4d5acac451dccaf276e69f0b49b72221eef5d2f\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [Jira XWiki](https://jira.xwiki.org/)\n* Email us at [XWiki Security mailing-list](mailto:security@xwiki.org)\n",
  "id": "GHSA-663w-2xp3-5739",
  "modified": "2023-11-01T06:06:17Z",
  "published": "2023-10-25T21:02:49Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/xwiki/xwiki-rendering/security/advisories/GHSA-663w-2xp3-5739"
    },
    {
      "type": "WEB",
      "url": "https://github.com/xwiki/xwiki-rendering/security/advisories/GHSA-6gf5-c898-7rxp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-37908"
    },
    {
      "type": "WEB",
      "url": "https://github.com/xwiki/xwiki-rendering/commit/f4d5acac451dccaf276e69f0b49b72221eef5d2f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/xwiki/xwiki-rendering"
    },
    {
      "type": "WEB",
      "url": "https://jira.xwiki.org/browse/XRENDERING-697"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "org.xwiki.rendering:xwiki-rendering-xml Improper Neutralization of Invalid Characters in Identifiers in Web Pages vulnerability"
}

GHSA-6GF5-C898-7RXP

Vulnerability from github – Published: 2023-05-11 20:37 – Updated: 2023-05-11 20:37
VLAI
Summary
Improper Neutralization of Script in Attributes in XWiki (X)HTML renderers
Details

Impact

HTML rendering didn't check for dangerous attributes/attribute values. This allowed cross-site scripting (XSS) attacks via attributes and link URLs, e.g., supported in XWiki syntax.

Patches

This has been patched in XWiki 14.6 RC1.

Workarounds

There are no known workarounds apart from upgrading to a fixed version.

References

  • https://github.com/xwiki/xwiki-rendering/commit/c40e2f5f9482ec6c3e71dbf1fff5ba8a5e44cdc1
  • https://jira.xwiki.org/browse/XRENDERING-663

For more information

If you have any questions or comments about this advisory: * Open an issue in Jira XWiki.org * Email us at Security Mailing List

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-syntax-xhtml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.platform:xwiki-core-rendering-api"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "3.0-milestone-2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-syntax-html"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-syntax-html5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-syntax-annotatedxhtml"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.rendering:xwiki-rendering-syntax-annotatedhtml5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.xwiki.platform:xwiki-platform-annotation-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "14.6-rc-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-32070"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79",
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-05-11T20:37:30Z",
    "nvd_published_at": "2023-05-10T18:15:10Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nHTML rendering didn\u0027t check for dangerous attributes/attribute values. This allowed cross-site scripting (XSS) attacks via attributes and link URLs, e.g., supported in XWiki syntax.\n\n### Patches\nThis has been patched in XWiki 14.6 RC1.\n\n### Workarounds\nThere are no known workarounds apart from upgrading to a fixed version.\n\n### References\n* https://github.com/xwiki/xwiki-rendering/commit/c40e2f5f9482ec6c3e71dbf1fff5ba8a5e44cdc1\n* https://jira.xwiki.org/browse/XRENDERING-663\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [Jira XWiki.org](https://jira.xwiki.org/)\n* Email us at [Security Mailing List](mailto:security@xwiki.org)\n",
  "id": "GHSA-6gf5-c898-7rxp",
  "modified": "2023-05-11T20:37:30Z",
  "published": "2023-05-11T20:37:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/xwiki/xwiki-rendering/security/advisories/GHSA-6gf5-c898-7rxp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-32070"
    },
    {
      "type": "WEB",
      "url": "https://github.com/xwiki/xwiki-rendering/commit/c40e2f5f9482ec6c3e71dbf1fff5ba8a5e44cdc1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/xwiki/xwiki-rendering"
    },
    {
      "type": "WEB",
      "url": "https://jira.xwiki.org/browse/XRENDERING-663"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Improper Neutralization of Script in Attributes in XWiki (X)HTML renderers"
}

GHSA-6XCG-6Q43-RJ2V

Vulnerability from github – Published: 2026-06-16 21:31 – Updated: 2026-06-18 20:13
VLAI
Summary
Duplicate Advisory: Exported session HTML could keep unsafe markdown links
Details

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-w9hf-3pp7-pvxv. This link is maintained to preserve external references.

Original Description

OpenClaw before 2026.5.12 contains a cross-site scripting vulnerability in exported session HTML that preserves unsafe javascript: and data: links in generated content. Attackers can execute browser-side scripts if a trusted operator opens the exported file and activates a malicious link.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "openclaw"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2026.5.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T20:13:59Z",
    "nvd_published_at": "2026-06-16T19:17:00Z",
    "severity": "LOW"
  },
  "details": "## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of\u00a0GHSA-w9hf-3pp7-pvxv. This link is maintained to preserve external references.\n\n## Original Description\nOpenClaw before 2026.5.12 contains a cross-site scripting vulnerability in exported session HTML that preserves unsafe javascript: and data: links in generated content. Attackers can execute browser-side scripts if a trusted operator opens the exported file and activates a malicious link.",
  "id": "GHSA-6xcg-6q43-rj2v",
  "modified": "2026-06-18T20:13:59Z",
  "published": "2026-06-16T21:31:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/openclaw/openclaw/security/advisories/GHSA-w9hf-3pp7-pvxv"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53841"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/openclaw-cross-site-scripting-via-unsafe-markdown-links-in-exported-session-html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Duplicate Advisory: Exported session HTML could keep unsafe markdown links",
  "withdrawn": "2026-06-18T20:13:59Z"
}

GHSA-779W-7MCF-PVXF

Vulnerability from github – Published: 2022-05-24 17:28 – Updated: 2025-06-05 00:31
VLAI
Details

Philips Clinical Collaboration Platform, Versions 12.2.1 and prior. The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output used as a webpage that is served to other users.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2020-14525"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-83"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-09-18T18:15:00Z",
    "severity": "LOW"
  },
  "details": "Philips Clinical Collaboration Platform, Versions 12.2.1 and prior. The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output used as a webpage that is served to other users.",
  "id": "GHSA-779w-7mcf-pvxf",
  "modified": "2025-06-05T00:31:18Z",
  "published": "2022-05-24T17:28:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-14525"
    },
    {
      "type": "WEB",
      "url": "https://us-cert.cisa.gov/ics/advisories/icsma-20-261-01"
    },
    {
      "type": "WEB",
      "url": "https://www.philips.com/a-w/security/security-advisories/product-security-2020.html#2020_archive"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-7F96-HG3W-W868

Vulnerability from github – Published: 2025-04-11 04:19 – Updated: 2025-04-11 04:19
VLAI
Details

An improper input neutralization vulnerability in the management web interface of the Palo Alto Networks PAN-OS® software enables a malicious authenticated read-write administrator to impersonate another legitimate authenticated PAN-OS administrator.

The attacker must have network access to the management web interface to exploit this issue. You greatly reduce the risk of this issue by restricting access to the management web interface to only trusted internal IP addresses according to our recommended critical deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

This issue does not affect Cloud NGFW and all Prisma® Access instances.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-0125"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-83"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-04-11T02:15:18Z",
    "severity": "MODERATE"
  },
  "details": "An improper input neutralization vulnerability in the management web interface of the Palo Alto Networks PAN-OS\u00ae software enables a malicious authenticated read-write administrator to impersonate another legitimate authenticated PAN-OS administrator.\n\n\nThe attacker must have network access to the management web interface to exploit this issue. You greatly reduce the risk of this issue by restricting access to the management web interface to only trusted internal IP addresses according to our recommended  critical deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .\n\nThis issue does not affect Cloud NGFW and all Prisma\u00ae Access instances.",
  "id": "GHSA-7f96-hg3w-w868",
  "modified": "2025-04-11T04:19:27Z",
  "published": "2025-04-11T04:19:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-0125"
    },
    {
      "type": "WEB",
      "url": "https://security.paloaltonetworks.com/CVE-2025-0125"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:N/R:U/V:C/RE:M/U:Amber",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-7PW4-F3Q4-R2P2

Vulnerability from github – Published: 2026-07-20 23:21 – Updated: 2026-08-12 20:37
VLAI
Summary
Astro: Cross-site scripting via unescaped transition:* directive values on hydrated islands
Details

Summary

When a transition:persist, transition:scope, or transition:persist-props directive is applied to a client-hydrated (client:*) component, Astro copied the directive value onto the rendered <astro-island> element without HTML-escaping it. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS).

Severity

Although a generic reflected XSS scores in the Medium range, exploitation here requires the application developer to have written a non-idiomatic pattern — passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This mitigating precondition places the real-world severity at Low.

Details

In generateHydrateScript() (packages/astro/src/runtime/server/hydration.ts), every island property is HTML-escaped before serialization — the attrs, props, and opts assignments all pass through escapeHTML(). The transition directives, however, were copied verbatim:

transitionDirectivesToCopyOnIsland.forEach((name) => {
  if (typeof props[name] !== 'undefined') {
    island.props[name] = props[name]; // not escaped
  }
});

The <astro-island> element is serialized via renderElement('astro-island', island, false) with shouldEscape=false, and toAttributeString() returns the value unchanged in that mode. As a result there is no downstream re-escaping, and the raw directive value reaches the HTML response. This is the same output sink previously addressed for slot names in GHSA-8hv8-536x-4wqp.

The affected directives are:

  • data-astro-transition-scope (transition:scope)
  • data-astro-transition-persist (transition:persist)
  • data-astro-transition-persist-props (transition:persist-props)

Note that transition:persist is typed boolean | string, so passing a string value is a supported use of the API.

Proof of Concept

A component that reflects a query parameter into a transition directive:

---
const persist = Astro.url.searchParams.get('persist') ?? 'default';
---
<Island client:load transition:persist={persist} />

Request:

https://example.com/?persist="><img src=x onerror=alert(document.domain)>

Rendered output (before the fix):

<astro-island … data-astro-transition-persist=""><img src=x onerror=alert(document.domain)>></astro-island>

The " closes the attribute and the injected <img onerror=…> executes in the victim's browser.

Impact

Reflected XSS. An attacker who can induce a victim to visit a crafted URL can execute arbitrary script in the victim's session on the origin, subject to the requirement that the target application reflects untrusted input into one of the affected transition directives.

Affected Versions

astro >= 3.10.0, < 7.0.4 (introduced in 3.10.0, PR #7861).

Patched Versions

astro >= 7.0.4. Fixed in PR #17212 by HTML-escaping transition directive values before they are rendered onto the island element.

Workarounds

Do not pass untrusted or request-derived input into transition:persist, transition:scope, or transition:persist-props. If such input is required, HTML-escape or strictly validate it before passing it to the directive. Upgrading to astro@7.0.4 or later removes the need for manual mitigation.

Credits

Reported by @jlgore.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "astro"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.10.0"
            },
            {
              "fixed": "7.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-59727"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-79",
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-20T23:21:02Z",
    "nvd_published_at": "2026-07-27T20:16:40Z",
    "severity": "LOW"
  },
  "details": "### Summary\n\nWhen a `transition:persist`, `transition:scope`, or `transition:persist-props` directive is applied to a client-hydrated (`client:*`) component, Astro copied the directive value onto the rendered `\u003castro-island\u003e` element **without HTML-escaping it**. If a developer reflects attacker-controlled input into one of these directives, an attacker can break out of the attribute and inject arbitrary HTML/JavaScript into the server-rendered output, resulting in reflected cross-site scripting (XSS).\n\n### Severity\n\nAlthough a generic reflected XSS scores in the Medium range, exploitation here requires the application developer to have written a non-idiomatic pattern \u2014 passing untrusted, request-derived input directly into a transition directive. Astro applications that do not route untrusted input into these directives are unaffected. This mitigating precondition places the real-world severity at Low.\n\n### Details\n\nIn `generateHydrateScript()` (`packages/astro/src/runtime/server/hydration.ts`), every island property is HTML-escaped before serialization \u2014 the `attrs`, `props`, and `opts` assignments all pass through `escapeHTML()`. The transition directives, however, were copied verbatim:\n\n```ts\ntransitionDirectivesToCopyOnIsland.forEach((name) =\u003e {\n  if (typeof props[name] !== \u0027undefined\u0027) {\n    island.props[name] = props[name]; // not escaped\n  }\n});\n```\n\nThe `\u003castro-island\u003e` element is serialized via `renderElement(\u0027astro-island\u0027, island, false)` with `shouldEscape=false`, and `toAttributeString()` returns the value unchanged in that mode. As a result there is no downstream re-escaping, and the raw directive value reaches the HTML response. This is the same output sink previously addressed for slot names in GHSA-8hv8-536x-4wqp.\n\nThe affected directives are:\n\n- `data-astro-transition-scope` (`transition:scope`)\n- `data-astro-transition-persist` (`transition:persist`)\n- `data-astro-transition-persist-props` (`transition:persist-props`)\n\nNote that `transition:persist` is typed `boolean | string`, so passing a string value is a supported use of the API.\n\n### Proof of Concept\n\nA component that reflects a query parameter into a transition directive:\n\n```astro\n---\nconst persist = Astro.url.searchParams.get(\u0027persist\u0027) ?? \u0027default\u0027;\n---\n\u003cIsland client:load transition:persist={persist} /\u003e\n```\n\nRequest:\n\n```\nhttps://example.com/?persist=\"\u003e\u003cimg src=x onerror=alert(document.domain)\u003e\n```\n\nRendered output (before the fix):\n\n```html\n\u003castro-island \u2026 data-astro-transition-persist=\"\"\u003e\u003cimg src=x onerror=alert(document.domain)\u003e\u003e\u003c/astro-island\u003e\n```\n\nThe `\"` closes the attribute and the injected `\u003cimg onerror=\u2026\u003e` executes in the victim\u0027s browser.\n\n### Impact\n\nReflected XSS. An attacker who can induce a victim to visit a crafted URL can execute arbitrary script in the victim\u0027s session on the origin, subject to the requirement that the target application reflects untrusted input into one of the affected transition directives.\n\n### Affected Versions\n\n`astro \u003e= 3.10.0, \u003c 7.0.4` (introduced in 3.10.0, PR #7861).\n\n### Patched Versions\n\n`astro \u003e= 7.0.4`. Fixed in PR #17212 by HTML-escaping transition directive values before they are rendered onto the island element.\n\n### Workarounds\n\nDo not pass untrusted or request-derived input into `transition:persist`, `transition:scope`, or `transition:persist-props`. If such input is required, HTML-escape or strictly validate it before passing it to the directive. Upgrading to `astro@7.0.4` or later removes the need for manual mitigation.\n\n### Credits\n\nReported by @jlgore.",
  "id": "GHSA-7pw4-f3q4-r2p2",
  "modified": "2026-08-12T20:37:24Z",
  "published": "2026-07-20T23:21:02Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/withastro/astro/security/advisories/GHSA-7pw4-f3q4-r2p2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59727"
    },
    {
      "type": "WEB",
      "url": "https://github.com/withastro/astro/pull/17212"
    },
    {
      "type": "WEB",
      "url": "https://github.com/withastro/astro/commit/7ba0bb1dc7516e88caff9abd7767322af44b0294"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/withastro/astro"
    },
    {
      "type": "WEB",
      "url": "https://github.com/withastro/astro/releases/tag/astro@7.0.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Astro: Cross-site scripting via unescaped transition:* directive values on hydrated islands"
}

GHSA-8M4F-V87C-8XHM

Vulnerability from github – Published: 2025-05-14 21:31 – Updated: 2025-05-14 21:31
VLAI
Details

An improper input neutralization vulnerability in the management web interface of the Palo Alto Networks PAN-OS® software enables a malicious authenticated read-write administrator to impersonate another legitimate authenticated PAN-OS administrator.

The attacker must have network access to the management web interface to exploit this issue. You greatly reduce the risk of this issue by restricting access to the management web interface to only trusted internal IP addresses according to our recommended critical deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-0137"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-83"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-05-14T19:15:52Z",
    "severity": "MODERATE"
  },
  "details": "An improper input neutralization vulnerability in the management web interface of the Palo Alto Networks PAN-OS\u00ae software enables a malicious authenticated read-write administrator to impersonate another legitimate authenticated PAN-OS administrator.\n\n\nThe attacker must have network access to the management web interface to exploit this issue. You greatly reduce the risk of this issue by restricting access to the management web interface to only trusted internal IP addresses according to our recommended  critical deployment guidelines https://live.paloaltonetworks.com/t5/community-blogs/tips-amp-tricks-how-to-secure-the-management-access-of-your-palo/ba-p/464431 .",
  "id": "GHSA-8m4f-v87c-8xhm",
  "modified": "2025-05-14T21:31:18Z",
  "published": "2025-05-14T21:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-0137"
    },
    {
      "type": "WEB",
      "url": "https://security.paloaltonetworks.com/CVE-2025-0137"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:N/R:U/V:C/RE:M/U:Amber",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-8RMJ-XGQ5-W9QM

Vulnerability from github – Published: 2026-08-04 18:31 – Updated: 2026-08-04 18:31
VLAI
Details

An issue was discovered in Django 5.2 before 5.2.17 and 6.0 before 6.0.8. django.contrib.admin.utils.display_for_field() renders URLField values as clickable links in the admin without validating the URL. A value stored with an unsafe scheme is displayed as a link on changelist and read-only admin pages, which allows cross-site scripting against staff users who click the link. Exploitation requires the unsafe value to already be stored in the database. URLField validation through a ModelForm or the admin rejects unsafe schemes, so this affects applications that persist URLField data without running model validation, for example through direct queryset writes, deserialization, or bulk import of untrusted input. Django would like to thank Egor Saltykov for reporting this issue.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-15920"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-83"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-04T17:16:46Z",
    "severity": "MODERATE"
  },
  "details": "An issue was discovered in Django 5.2 before 5.2.17 and 6.0 before 6.0.8.\n`django.contrib.admin.utils.display_for_field()` renders `URLField` values as clickable links in the admin without validating the URL. A value stored with an unsafe scheme is displayed as a link on changelist and read-only admin pages, which allows cross-site scripting against staff users who click the link.\nExploitation requires the unsafe value to already be stored in the database. `URLField` validation through a `ModelForm` or the admin rejects unsafe schemes, so this affects applications that persist `URLField` data without running model validation, for example through direct queryset writes, deserialization, or bulk import of untrusted input.\nDjango would like to thank Egor Saltykov for reporting this issue.",
  "id": "GHSA-8rmj-xgq5-w9qm",
  "modified": "2026-08-04T18:31:27Z",
  "published": "2026-08-04T18:31:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-15920"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/13debb622a32720bda1bccda7622fd14fbf3931b"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/47511a21026cdd721d8fbf8571cc079bc38bb46d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/5a260d309a4c8010c2ebda24eb758a5d95e2508a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/django/django/commit/b9adb81339cc418f8f56b1050cca6dfec3ab6349"
    },
    {
      "type": "WEB",
      "url": "https://docs.djangoproject.com/en/dev/releases/security"
    },
    {
      "type": "WEB",
      "url": "https://groups.google.com/g/django-announce"
    },
    {
      "type": "WEB",
      "url": "https://www.djangoproject.com/weblog/2026/aug/04/security-releases"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-934W-87QH-QR26

Vulnerability from github – Published: 2026-06-16 13:49 – Updated: 2026-08-14 18:45
VLAI
Summary
Nuxt: Reflected XSS in `<NuxtLink>` via unsanitised `javascript:` or `data:` URL
Details

Summary

<NuxtLink> did not validate the URL scheme of values bound to its to or href props before rendering them into the href attribute of the underlying <a> element. When an application binds attacker-controlled input (a query parameter, a CMS field, a user-supplied profile URL) to <NuxtLink :to> or :href, the attacker can supply a javascript: or vbscript: URL that is reflected verbatim into the rendered markup. Clicking the link executes the supplied script in the origin of the Nuxt application, resulting in reflected DOM-based cross-site scripting. A data:text/html,... payload reflected through the same sink does not execute in the application's origin but enables a same-tab phishing surface anchored to a legitimate application link.

The same value was exposed to consumers of the component's custom slot via the href and route.href props, so applications that re-bind those values to their own anchors were affected identically.

Unlike the previously reported navigateTo issue (CVE-2024-34343), the sink here is the rendered anchor itself; the existing isScriptProtocol checks in navigateTo and reloadNuxtApp are not on the code path. The onClick handler intentionally returns early for external links so the browser's native protocol-based navigation runs.

Affected component

  • File: packages/nuxt/src/app/components/nuxt-link.ts
  • Sink: h('a', { href: href.value, ... }) in the default render, plus the href / route.href props passed to the custom slot.
  • Broken check: external auto-detection treated any hasProtocol(path, { acceptRelative: true }) value as an "external link", then rendered the value directly as <a href> without rejecting script-capable protocols. There was no equivalent of the navigateTo isScriptProtocol(protocol) gate in this path.

Impact

Any Nuxt application that binds user-controlled values to <NuxtLink :to> / :href was vulnerable. Common shapes: profile-link rendering (<NuxtLink :to="user.website">), "share this" / "open in new tab" handlers that pass through a query parameter, CMS-driven landing pages that render <NuxtLink :to="cms.cta.url">, and marketplace listings that show seller-supplied links.

For javascript: / vbscript: the primitive is reflected XSS in the application's first-party origin (session theft for non-HttpOnly cookies, CSRF token theft, account takeover via DOM rewriting, credential harvesting via fake login overlays). For data:text/html,... the attacker gets a same-tab phishing surface anchored to a legitimate application link.

Patches

Fixed in nuxt@4.4.7 (commit 0103ce06) and backported to nuxt@3.21.7 (commit 53284043). The fix sanitises the resolved external href before it is passed to <a> or the custom slot: control characters and whitespace are stripped, leading view-source: prefixes are unwrapped, and any remaining script-capable scheme (per isScriptProtocol) causes the href to be replaced with an empty string.

Workarounds

Until you can upgrade, validate URLs at the source before binding them to <NuxtLink :to> / :href. For example, only accept paths that start with / (and not //), or run user-supplied URLs through new URL(value) and reject anything whose protocol is not in an allow-list (typically http: and https:).

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "nuxt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.4.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "nuxt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.21.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-53722"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79",
      "CWE-83"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-16T13:49:36Z",
    "nvd_published_at": "2026-06-12T15:16:31Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\n`\u003cNuxtLink\u003e` did not validate the URL scheme of values bound to its `to` or `href` props before rendering them into the `href` attribute of the underlying `\u003ca\u003e` element. When an application binds attacker-controlled input (a query parameter, a CMS field, a user-supplied profile URL) to `\u003cNuxtLink :to\u003e` or `:href`, the attacker can supply a `javascript:` or `vbscript:` URL that is reflected verbatim into the rendered markup. Clicking the link executes the supplied script in the origin of the Nuxt application, resulting in reflected DOM-based cross-site scripting. A `data:text/html,...` payload reflected through the same sink does not execute in the application\u0027s origin but enables a same-tab phishing surface anchored to a legitimate application link.\n\nThe same value was exposed to consumers of the component\u0027s `custom` slot via the `href` and `route.href` props, so applications that re-bind those values to their own anchors were affected identically.\n\nUnlike the previously reported `navigateTo` issue (CVE-2024-34343), the sink here is the rendered anchor itself; the existing `isScriptProtocol` checks in `navigateTo` and `reloadNuxtApp` are not on the code path. The `onClick` handler intentionally returns early for external links so the browser\u0027s native protocol-based navigation runs.\n\n### Affected component\n\n- File: `packages/nuxt/src/app/components/nuxt-link.ts`\n- Sink: `h(\u0027a\u0027, { href: href.value, ... })` in the default render, plus the `href` / `route.href` props passed to the `custom` slot.\n- Broken check: external auto-detection treated any `hasProtocol(path, { acceptRelative: true })` value as an \"external link\", then rendered the value directly as `\u003ca href\u003e` without rejecting script-capable protocols. There was no equivalent of the `navigateTo` `isScriptProtocol(protocol)` gate in this path.\n\n### Impact\n\nAny Nuxt application that binds user-controlled values to `\u003cNuxtLink :to\u003e` / `:href` was vulnerable. Common shapes: profile-link rendering (`\u003cNuxtLink :to=\"user.website\"\u003e`), \"share this\" / \"open in new tab\" handlers that pass through a query parameter, CMS-driven landing pages that render `\u003cNuxtLink :to=\"cms.cta.url\"\u003e`, and marketplace listings that show seller-supplied links.\n\nFor `javascript:` / `vbscript:` the primitive is reflected XSS in the application\u0027s first-party origin (session theft for non-`HttpOnly` cookies, CSRF token theft, account takeover via DOM rewriting, credential harvesting via fake login overlays). For `data:text/html,...` the attacker gets a same-tab phishing surface anchored to a legitimate application link.\n\n### Patches\n\nFixed in `nuxt@4.4.7` (commit [`0103ce06`](https://github.com/nuxt/nuxt/commit/0103ce06fbbbdfa079a7f020ef8ce00121eac4a3)) and backported to `nuxt@3.21.7` (commit [`53284043`](https://github.com/nuxt/nuxt/commit/53284043dc21210a25d629d1cec67d3ae557ffd0)). The fix sanitises the resolved external `href` before it is passed to `\u003ca\u003e` or the `custom` slot: control characters and whitespace are stripped, leading `view-source:` prefixes are unwrapped, and any remaining script-capable scheme (per `isScriptProtocol`) causes the `href` to be replaced with an empty string.\n\n### Workarounds\n\nUntil you can upgrade, validate URLs at the source before binding them to `\u003cNuxtLink :to\u003e` / `:href`. For example, only accept paths that start with `/` (and not `//`), or run user-supplied URLs through `new URL(value)` and reject anything whose `protocol` is not in an allow-list (typically `http:` and `https:`).",
  "id": "GHSA-934w-87qh-qr26",
  "modified": "2026-08-14T18:45:56Z",
  "published": "2026-06-16T13:49:36Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/security/advisories/GHSA-934w-87qh-qr26"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53722"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/0103ce06fbbbdfa079a7f020ef8ce00121eac4a3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nuxt/nuxt/commit/53284043dc21210a25d629d1cec67d3ae557ffd0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/nuxt/nuxt"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Nuxt: Reflected XSS in `\u003cNuxtLink\u003e` via unsanitised `javascript:` or `data:` URL"
}

Mitigation
Implementation

Carefully check each input parameter against a rigorous positive specification (allowlist) defining the specific characters and format allowed. All input should be neutralized, not just parameters that the user is supposed to specify, but all data in the request, including tag attributes, hidden fields, cookies, headers, the URL itself, and so forth. A common mistake that leads to continuing XSS vulnerabilities is to validate only fields that are expected to be redisplayed by the site. We often encounter data from the request that is reflected by the application server or the application that the development team did not anticipate. Also, a field that is not currently reflected may be used by a future developer. Therefore, validating ALL parts of the HTTP request is recommended.

Mitigation MIT-30.1
Implementation

Strategy: Output Encoding

  • Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.
  • The problem of inconsistent output encodings often arises in web pages. If an encoding is not specified in an HTTP header, web browsers often guess about which encoding is being used. This can open up the browser to subtle XSS attacks.
Mitigation MIT-43
Implementation

With Struts, write all data from form beans with the bean's filter attribute set to true.

Mitigation MIT-31
Implementation

Strategy: Attack Surface Reduction

To help mitigate XSS attacks against the user's session cookie, set the session cookie to be HttpOnly. In browsers that support the HttpOnly feature (such as more recent versions of Internet Explorer and Firefox), this attribute can prevent the user's session cookie from being accessible to malicious client-side scripts that use document.cookie. This is not a complete solution, since HttpOnly is not supported by all browsers. More importantly, XmlHttpRequest and other powerful browser technologies provide read access to HTTP headers, including the Set-Cookie header in which the HttpOnly flag is set.

CAPEC-243: XSS Targeting HTML Attributes

An adversary inserts commands to perform cross-site scripting (XSS) actions in HTML attributes. Many filters do not adequately sanitize attributes against the presence of potentially dangerous commands even if they adequately sanitize tags. For example, dangerous expressions could be inserted into a style attribute in an anchor tag, resulting in the execution of malicious code when the resulting page is rendered. If a victim is tricked into viewing the rendered page the attack proceeds like a normal XSS attack, possibly resulting in the loss of sensitive cookies or other malicious activities.

CAPEC-244: XSS Targeting URI Placeholders

An attack of this type exploits the ability of most browsers to interpret "data", "javascript" or other URI schemes as client-side executable content placeholders. This attack consists of passing a malicious URI in an anchor tag HREF attribute or any other similar attributes in other HTML tags. Such malicious URI contains, for example, a base64 encoded HTML content with an embedded cross-site scripting payload. The attack is executed when the browser interprets the malicious content i.e., for example, when the victim clicks on the malicious link.

CAPEC-588: DOM-Based XSS

This type of attack is a form of Cross-Site Scripting (XSS) where a malicious script is inserted into the client-side HTML being parsed by a web browser. Content served by a vulnerable web application includes script code used to manipulate the Document Object Model (DOM). This script code either does not properly validate input, or does not perform proper output encoding, thus creating an opportunity for an adversary to inject a malicious script launch a XSS attack. A key distinction between other XSS attacks and DOM-based attacks is that in other XSS attacks, the malicious script runs when the vulnerable web page is initially loaded, while a DOM-based attack executes sometime after the page loads. Another distinction of DOM-based attacks is that in some cases, the malicious script is never sent to the vulnerable web server at all. An attack like this is guaranteed to bypass any server-side filtering attempts to protect users.