Vulnerability-Lookup

ubuntu-cve-2021-34557

Vulnerability from osv_ubuntu

Published

2021-06-10 16:15

Modified

2025-10-24 04:50

Summary

Details

XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.

Severity

4.6 (Medium)


                    
                      CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2021-34557	REPORT
	https://www.openwall.com/lists/oss-security/2021/…	REPORT
	https://www.openwall.com/lists/oss-security/2021/…	REPORT
	https://github.com/QubesOS/qubes-xscreensaver/blo…	REPORT
	https://github.com/QubesOS/qubes-issues/issues/6595	REPORT
	https://github.com/QubesOS/qubes-secpack/blob/mas…	REPORT
	https://www.cve.org/CVERecord?id=CVE-2021-34557	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "xscreensaver",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data-extra",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl-extra",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-bsod",
            "binary_version": "5.34-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-webcollage",
            "binary_version": "5.34-2ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:16.04:LTS",
        "name": "xscreensaver",
        "purl": "pkg:deb/ubuntu/xscreensaver@5.34-2ubuntu1?arch=source\u0026distro=xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.30-1ubuntu1",
        "5.34-1ubuntu1",
        "5.34-2ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "xscreensaver",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data-extra",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl-extra",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-bsod",
            "binary_version": "5.36-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-webcollage",
            "binary_version": "5.36-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:18.04:LTS",
        "name": "xscreensaver",
        "purl": "pkg:deb/ubuntu/xscreensaver@5.36-1ubuntu1?arch=source\u0026distro=bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.36-1ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "xscreensaver",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data-extra",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl-extra",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-bsod",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-webcollage",
            "binary_version": "5.42+dfsg1-1ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:20.04:LTS",
        "name": "xscreensaver",
        "purl": "pkg:deb/ubuntu/xscreensaver@5.42+dfsg1-1ubuntu1?arch=source\u0026distro=focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.42+dfsg1-1ubuntu1"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "xscreensaver",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-data-extra",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-gl-extra",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-bsod",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          },
          {
            "binary_name": "xscreensaver-screensaver-webcollage",
            "binary_version": "5.45+dfsg1-2ubuntu1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "xscreensaver",
        "purl": "pkg:deb/ubuntu/xscreensaver@5.45+dfsg1-2ubuntu1?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.45+dfsg1-2ubuntu1"
      ]
    }
  ],
  "aliases": [],
  "details": "XScreenSaver 5.45 can be bypassed if the machine has more than ten disconnectable video outputs. A buffer overflow in update_screen_layout() allows an attacker to bypass the standard screen lock authentication mechanism by crashing XScreenSaver. The attacker must physically disconnect many video outputs.",
  "id": "UBUNTU-CVE-2021-34557",
  "modified": "2025-10-24T04:50:24Z",
  "published": "2021-06-10T16:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2021-34557"
    },
    {
      "type": "REPORT",
      "url": "https://www.openwall.com/lists/oss-security/2021/06/05/1"
    },
    {
      "type": "REPORT",
      "url": "https://www.openwall.com/lists/oss-security/2021/06/05/2"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/QubesOS/qubes-issues/issues/6595"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2021-34557"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2021-34557"
  ]
}

CVE-2021-34557 (GCVE-0-2021-34557)

Vulnerability from cvelistv5 – Published: 2021-06-10 15:54 – Updated: 2024-08-04 00:12

Summary

Severity

No CVSS data available.

CWE

Assigner

mitre

References

7 references

URL	Tags
https://github.com/QubesOS/qubes-issues/issues/6595	x_refsource_MISC
https://www.openwall.com/lists/oss-security/2021/…	x_refsource_MISC
https://github.com/QubesOS/qubes-secpack/blob/mas…	x_refsource_MISC
https://github.com/QubesOS/qubes-xscreensaver/blo…	x_refsource_MISC
http://www.openwall.com/lists/oss-security/2021/06/11/1	mailing-listx_refsource_MLIST
http://www.openwall.com/lists/oss-security/2021/07/06/2	mailing-listx_refsource_MLIST
https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA

Show details on NVD website

JSON

To clipboard

{
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        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/QubesOS/qubes-issues/issues/6595"
          },
          {
            "tags": [
              "x_refsource_MISC",
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            "url": "https://www.openwall.com/lists/oss-security/2021/06/05/1"
          },
          {
            "tags": [
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            "url": "https://github.com/QubesOS/qubes-secpack/blob/master/QSBs/qsb-068-2021.txt"
          },
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            "url": "https://github.com/QubesOS/qubes-xscreensaver/blob/master/0001-Fix-updating-outputs-info.patch"
          },
          {
            "name": "[oss-security] 20210611 Re: XScreenSaver 5.45: Disconnecting a video output can cause XScreenSaver to crash and unlock",
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        ],
        "title": "CVE Program Container"
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    "cna": {
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    "datePublished": "2021-06-10T15:54:35.000Z",
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

ubuntu-cve-2021-34557

Vulnerability from osv_ubuntu

CVE-2021-34557 (GCVE-0-2021-34557)

Tags

Sightings

Nomenclature