CWE-770
AllowedAllocation of Resources Without Limits or Throttling
Abstraction: Base · Status: Incomplete
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
3029 vulnerabilities reference this CWE, most recent first.
GHSA-WJCC-8XX5-FRQG
Vulnerability from github – Published: 2022-10-07 18:16 – Updated: 2022-10-13 19:00In ISC DHCP 1.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1 a system with access to a DHCP server, sending DHCP packets crafted to include fqdn labels longer than 63 bytes, could eventually cause the server to run out of memory.
{
"affected": [],
"aliases": [
"CVE-2022-2929"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-10-07T05:15:00Z",
"severity": "MODERATE"
},
"details": "In ISC DHCP 1.0 -\u003e 4.4.3, ISC DHCP 4.1-ESV-R1 -\u003e 4.1-ESV-R16-P1 a system with access to a DHCP server, sending DHCP packets crafted to include fqdn labels longer than 63 bytes, could eventually cause the server to run out of memory.",
"id": "GHSA-wjcc-8xx5-frqg",
"modified": "2022-10-13T19:00:22Z",
"published": "2022-10-07T18:16:01Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-2929"
},
{
"type": "WEB",
"url": "https://kb.isc.org/docs/cve-2022-2929"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2022/10/msg00015.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2SARIK7KZ7MGQIWDRWZFAOSQSPXY4GOU"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QQXYCIWUDILRCNBAIMVFCSGXBRKEPB4K"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T6IBFH4MRRNJQVWEKILQ6I6CXWW766FX"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202305-22"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WJH5-4FQ2-439W
Vulnerability from github – Published: 2022-05-13 01:42 – Updated: 2022-05-13 01:42The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks due to IP fragmentation.
{
"affected": [],
"aliases": [
"CVE-2017-12132"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2017-08-01T16:29:00Z",
"severity": "MODERATE"
},
"details": "The DNS stub resolver in the GNU C Library (aka glibc or libc6) before version 2.26, when EDNS support is enabled, will solicit large UDP responses from name servers, potentially simplifying off-path DNS spoofing attacks due to IP fragmentation.",
"id": "GHSA-wjh5-4fq2-439w",
"modified": "2022-05-13T01:42:38Z",
"published": "2022-05-13T01:42:38Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-12132"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2018:0805"
},
{
"type": "WEB",
"url": "https://arxiv.org/pdf/1205.4011.pdf"
},
{
"type": "WEB",
"url": "https://sourceware.org/bugzilla/show_bug.cgi?id=21361"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/100598"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-WJH7-HP74-8R7H
Vulnerability from github – Published: 2025-06-12 12:32 – Updated: 2025-06-12 12:32An issue has been discovered in GitLab CE/EE affecting all versions from 2.1.0 before 17.10.8, 17.11 before 17.11.4, and 18.0 before 18.0.2. A lack of input validation in HTTP responses could allow an authenticated user to cause denial of service.
{
"affected": [],
"aliases": [
"CVE-2025-5996"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-12T10:16:39Z",
"severity": "MODERATE"
},
"details": "An issue has been discovered in GitLab CE/EE affecting all versions from 2.1.0 before 17.10.8, 17.11 before 17.11.4, and 18.0 before 18.0.2. A lack of input validation in HTTP responses could allow an authenticated user to cause denial of service.",
"id": "GHSA-wjh7-hp74-8r7h",
"modified": "2025-06-12T12:32:04Z",
"published": "2025-06-12T12:32:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-5996"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/476671"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/479167"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/483111"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/483150"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/498649"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WJQC-6W8F-H24C
Vulnerability from github – Published: 2026-06-16 13:45 – Updated: 2026-06-16 13:45Impact
An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing large XMP metadata, possibly with lots of unnecessary elements.
Patches
This has been fixed in pypdf==6.12.1.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3796.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "pypdf"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.12.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-48735"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-16T13:45:58Z",
"nvd_published_at": "2026-05-28T16:16:29Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nAn attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing large XMP metadata, possibly with lots of unnecessary elements.\n\n### Patches\nThis has been fixed in [pypdf==6.12.1](https://github.com/py-pdf/pypdf/releases/tag/6.12.1).\n\n### Workarounds\nIf you cannot upgrade yet, consider applying the changes from PR [#3796](https://github.com/py-pdf/pypdf/pull/3796).",
"id": "GHSA-wjqc-6w8f-h24c",
"modified": "2026-06-16T13:45:58Z",
"published": "2026-06-16T13:45:58Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-wjqc-6w8f-h24c"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48735"
},
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/pull/3796"
},
{
"type": "PACKAGE",
"url": "https://github.com/py-pdf/pypdf"
},
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/releases/tag/6.12.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "pypdf: Manipulated XMP metadata streams can exhaust RAM"
}
GHSA-WM64-HHRX-W2H7
Vulnerability from github – Published: 2023-04-16 00:30 – Updated: 2024-04-04 03:29An issue was discovered in GitLab Community and Enterprise Edition before 11.1.7, 11.2.x before 11.2.4, and 11.3.x before 11.3.1. The diff formatter using rouge can block for a long time in Sidekiq jobs without any timeout.
{
"affected": [],
"aliases": [
"CVE-2018-15472"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-04-15T23:15:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in GitLab Community and Enterprise Edition before 11.1.7, 11.2.x before 11.2.4, and 11.3.x before 11.3.1. The diff formatter using rouge can block for a long time in Sidekiq jobs without any timeout.",
"id": "GHSA-wm64-hhrx-w2h7",
"modified": "2024-04-04T03:29:38Z",
"published": "2023-04-16T00:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-15472"
},
{
"type": "WEB",
"url": "https://about.gitlab.com/blog/categories/releases"
},
{
"type": "WEB",
"url": "https://about.gitlab.com/releases/2018/10/01/security-release-gitlab-11-dot-3-dot-1-released"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WM6P-93J5-RX57
Vulnerability from github – Published: 2024-05-14 15:32 – Updated: 2026-04-02 21:31The issue was addressed with improved memory handling. This issue is fixed in iOS 17.5 and iPadOS 17.5, tvOS 17.5, watchOS 10.5, macOS Sonoma 14.5. An app may be able to execute arbitrary code with kernel privileges.
{
"affected": [],
"aliases": [
"CVE-2024-27804"
],
"database_specific": {
"cwe_ids": [
"CWE-1325",
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-14T15:13:04Z",
"severity": "HIGH"
},
"details": "The issue was addressed with improved memory handling. This issue is fixed in iOS 17.5 and iPadOS 17.5, tvOS 17.5, watchOS 10.5, macOS Sonoma 14.5. An app may be able to execute arbitrary code with kernel privileges.",
"id": "GHSA-wm6p-93j5-rx57",
"modified": "2026-04-02T21:31:40Z",
"published": "2024-05-14T15:32:53Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-27804"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/120901"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/120902"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/120903"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/120905"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/120915"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/HT214101"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/HT214102"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/HT214104"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/HT214106"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT214101"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT214102"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT214104"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT214106"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT214123"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2024/Jul/23"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2024/May/10"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2024/May/12"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2024/May/16"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2024/May/17"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WM99-2G28-JP5M
Vulnerability from github – Published: 2024-04-04 09:30 – Updated: 2026-02-06 18:30In the Linux kernel, the following vulnerability has been resolved:
fbcon: always restore the old font data in fbcon_do_set_font()
Commit a5a923038d70 (fbdev: fbcon: Properly revert changes when vc_resize() failed) started restoring old font data upon failure (of vc_resize()). But it performs so only for user fonts. It means that the "system"/internal fonts are not restored at all. So in result, the very first call to fbcon_do_set_font() performs no restore at all upon failing vc_resize().
This can be reproduced by Syzkaller to crash the system on the next invocation of font_get(). It's rather hard to hit the allocation failure in vc_resize() on the first font_set(), but not impossible. Esp. if fault injection is used to aid the execution/failure. It was demonstrated by Sirius: BUG: unable to handle page fault for address: fffffffffffffff8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286 Call Trace: con_font_get drivers/tty/vt/vt.c:4558 [inline] con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803 vfs_ioctl fs/ioctl.c:51 [inline] ...
So restore the font data in any case, not only for user fonts. Note the later 'if' is now protected by 'old_userfont' and not 'old_data' as the latter is always set now. (And it is supposed to be non-NULL. Otherwise we would see the bug above again.)
{
"affected": [],
"aliases": [
"CVE-2024-26798"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-04T09:15:08Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbcon: always restore the old font data in fbcon_do_set_font()\n\nCommit a5a923038d70 (fbdev: fbcon: Properly revert changes when\nvc_resize() failed) started restoring old font data upon failure (of\nvc_resize()). But it performs so only for user fonts. It means that the\n\"system\"/internal fonts are not restored at all. So in result, the very\nfirst call to fbcon_do_set_font() performs no restore at all upon\nfailing vc_resize().\n\nThis can be reproduced by Syzkaller to crash the system on the next\ninvocation of font_get(). It\u0027s rather hard to hit the allocation failure\nin vc_resize() on the first font_set(), but not impossible. Esp. if\nfault injection is used to aid the execution/failure. It was\ndemonstrated by Sirius:\n BUG: unable to handle page fault for address: fffffffffffffff8\n #PF: supervisor read access in kernel mode\n #PF: error_code(0x0000) - not-present page\n PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0\n Oops: 0000 [#1] PREEMPT SMP KASAN\n CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014\n RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286\n Call Trace:\n \u003cTASK\u003e\n con_font_get drivers/tty/vt/vt.c:4558 [inline]\n con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673\n vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]\n vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752\n tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803\n vfs_ioctl fs/ioctl.c:51 [inline]\n ...\n\nSo restore the font data in any case, not only for user fonts. Note the\nlater \u0027if\u0027 is now protected by \u0027old_userfont\u0027 and not \u0027old_data\u0027 as the\nlatter is always set now. (And it is supposed to be non-NULL. Otherwise\nwe would see the bug above again.)",
"id": "GHSA-wm99-2g28-jp5m",
"modified": "2026-02-06T18:30:26Z",
"published": "2024-04-04T09:30:36Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26798"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/20a4b5214f7bee13c897477168c77bbf79683c3d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2f91a96b892fab2f2543b4a55740c5bee36b1a6b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/73a6bd68a1342f3a44cac9dffad81ad6a003e520"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a2c881413dcc5d801bdc9535e51270cc88cb9cd8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ae68f57df3335679653868fafccd8c88ef84ae98"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-WMG4-8CP2-HPG9
Vulnerability from github – Published: 2021-04-19 14:54 – Updated: 2024-09-24 15:43Impact
Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to disk space exhaustion and denial of service.
Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service.
This affects any server which accepts registration requests from untrusted clients.
Patches
Patched by 89071a1, 0523511, f56eee3.
Workarounds
Request sizes can be limited in an HTTP reverse-proxy.
There are no known workarounds for the problem with overlarge responses.
For more information
If you have any questions or comments about this advisory, email us at security@matrix.org.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "matrix-sydent"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.3.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2021-29430"
],
"database_specific": {
"cwe_ids": [
"CWE-20",
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2021-04-15T20:49:34Z",
"nvd_published_at": "2021-04-15T21:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\n\nSydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to disk space exhaustion and denial of service.\n\nSydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service.\n\nThis affects any server which accepts registration requests from untrusted clients.\n\n### Patches\n\nPatched by 89071a1, 0523511, f56eee3.\n\n### Workarounds\n\nRequest sizes can be limited in an HTTP reverse-proxy.\n\nThere are no known workarounds for the problem with overlarge responses.\n\n### For more information\n\nIf you have any questions or comments about this advisory, email us at security@matrix.org.",
"id": "GHSA-wmg4-8cp2-hpg9",
"modified": "2024-09-24T15:43:44Z",
"published": "2021-04-19T14:54:04Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-29430"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"
},
{
"type": "PACKAGE",
"url": "https://github.com/matrix-org/sydent"
},
{
"type": "WEB",
"url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/matrix-sydent/PYSEC-2021-21.yaml"
},
{
"type": "WEB",
"url": "https://pypi.org/project/matrix-sydent"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Sydent vulnerable to denial of service attack via memory exhaustion"
}
GHSA-WPHV-VFRH-23Q5
Vulnerability from github – Published: 2026-06-26 20:59 – Updated: 2026-06-26 20:59RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization
Summary
Testing revealed that joserfc accepts oversized RFC7797 b64=false JWS payloads without applying JWSRegistry.max_payload_length.
The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with ExceededSizeError. The RFC7797 unencoded payload paths do not make the same check. A valid b64=false compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than JWSRegistry.max_payload_length.
This creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on joserfc to reject oversized token content during verification.
Affected Product
- Package:
joserfc - Ecosystem:
pip - Audited release:
1.6.5 - Audit tag:
1.6.5 - Audit commit:
881712980934fb601bed26fe3ae1ec0b7780e6f7 - Tested affected releases:
1.3.4,1.3.5,1.4.2,1.6.2,1.6.3,1.6.4,1.6.5 - Fixed release: none known
Vulnerability Details
In joserfc 1.6.5, the default JWS registry has max_payload_length = 128000 and exposes validate_payload_size().
The normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly:
if is_rfc7797_enabled(protected):
if not payload_segment and payload:
payload_segment = to_bytes(payload)
payload = payload_segment
The flattened JSON RFC7797 path has the same pattern:
payload_segment = value["payload"].encode("utf-8")
if is_rfc7797_enabled(member.headers()):
payload = payload_segment
Neither branch calls registry.validate_payload_size(payload_segment) before accepting the unencoded payload.
Reproduction
The proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 b64=false behavior.
Requirements:
python -m pip install "joserfc==1.6.5"
Run:
python joserfc_rfc7797_size_bypass_poc.py
Self-contained proof script:
#!/usr/bin/env python3
import json
import joserfc
from joserfc import jws
from joserfc.jwk import OctKey
def check_compact(name, header, payload, key):
token = jws.serialize_compact(header, payload, key)
try:
obj = jws.deserialize_compact(token, key)
return {
"case": name,
"accepted": True,
"exception": None,
"payload_len_after_deserialize": len(obj.payload),
}
except Exception as exc:
return {
"case": name,
"accepted": False,
"exception": type(exc).__name__,
"error": str(exc),
}
def check_json(name, protected, payload, key):
data = jws.serialize_json({"protected": protected}, payload, key)
try:
obj = jws.deserialize_json(data, key)
return {
"case": name,
"accepted": True,
"exception": None,
"payload_len_after_deserialize": len(obj.payload),
}
except Exception as exc:
return {
"case": name,
"accepted": False,
"exception": type(exc).__name__,
"error": str(exc),
}
key = OctKey.import_key("secret-secret-secret")
limit = jws.default_registry.max_payload_length
payload = "A" * (limit + 1)
results = {
"joserfc_version": joserfc.__version__,
"default_max_payload_length": limit,
"payload_len": len(payload),
"compact": [
check_compact("normal_b64_true", {"alg": "HS256"}, payload, key),
check_compact(
"rfc7797_b64_false",
{"alg": "HS256", "b64": False, "crit": ["b64"]},
payload,
key,
),
],
"json": [
check_json("normal_b64_true_json", {"alg": "HS256"}, payload, key),
check_json(
"rfc7797_b64_false_json",
{"alg": "HS256", "b64": False, "crit": ["b64"]},
payload,
key,
),
],
}
print(json.dumps(results, indent=2, sort_keys=True))
Expected output on 1.6.5 includes:
{
"default_max_payload_length": 128000,
"payload_len": 128001,
"compact": [
{
"case": "normal_b64_true",
"accepted": false,
"exception": "ExceededSizeError"
},
{
"case": "rfc7797_b64_false",
"accepted": true,
"exception": null,
"payload_len_after_deserialize": 128001
}
],
"json": [
{
"case": "normal_b64_true_json",
"accepted": false,
"exception": "ExceededSizeError"
},
{
"case": "rfc7797_b64_false_json",
"accepted": true,
"exception": null,
"payload_len_after_deserialize": 128001
}
]
}
Version Checks
I reproduced the same differential behavior on these releases:
| Version | Normal JWS over limit | RFC7797 b64=false over limit |
|---|---|---|
| 1.3.4 | ExceededSizeError |
accepted |
| 1.3.5 | ExceededSizeError |
accepted |
| 1.4.2 | ExceededSizeError |
accepted |
| 1.6.2 | ExceededSizeError |
accepted |
| 1.6.3 | ExceededSizeError |
accepted |
| 1.6.4 | ExceededSizeError |
accepted |
| 1.6.5 | ExceededSizeError |
accepted |
The exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it.
Relationship to Existing Advisories
I found two related public advisories for joserfc, but neither appears to cover this root cause.
GHSA-frfh-8v73-gjg4 / CVE-2025-65015 describes oversized token parts being included in ExceededSizeError messages in older release ranges. The issue described here reproduces in 1.6.5 and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising ExceededSizeError.
GHSA-w5r5-m38g-f9f9 / CVE-2026-27932 describes unbounded PBES2 p2c iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption.
Workarounds
Before a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to joserfc, disabling or disallowing RFC7797 b64=false tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer.
Suggested Remediation
Apply registry.validate_payload_size(payload_segment) to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the payload argument should be checked in the same way.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "joserfc"
},
"ranges": [
{
"events": [
{
"introduced": "1.3.4"
},
{
"fixed": "1.6.7"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-48990"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-26T20:59:38Z",
"nvd_published_at": "2026-06-17T22:16:23Z",
"severity": "MODERATE"
},
"details": "# RFC7797 b64=false JWS payloads bypass JWSRegistry payload-size limits during deserialization\n\n## Summary\n\nTesting revealed that `joserfc` accepts oversized RFC7797 `b64=false` JWS payloads without applying `JWSRegistry.max_payload_length`.\n\nThe normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with `ExceededSizeError`. The RFC7797 unencoded payload paths do not make the same check. A valid `b64=false` compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than `JWSRegistry.max_payload_length`.\n\nThis creates a moderate availability/resource-exhaustion risk for applications that accept lower-trust JWS values and rely on `joserfc` to reject oversized token content during verification.\n\n## Affected Product\n\n- Package: `joserfc`\n- Ecosystem: `pip`\n- Audited release: `1.6.5`\n- Audit tag: `1.6.5`\n- Audit commit: `881712980934fb601bed26fe3ae1ec0b7780e6f7`\n- Tested affected releases: `1.3.4`, `1.3.5`, `1.4.2`, `1.6.2`, `1.6.3`, `1.6.4`, `1.6.5`\n- Fixed release: none known\n\n## Vulnerability Details\n\nIn `joserfc` 1.6.5, the default JWS registry has `max_payload_length = 128000` and exposes `validate_payload_size()`.\n\nThe normal compact extraction path calls that check before base64url-decoding the payload. The RFC7797 compact path validates the header and signature segment sizes, then assigns the unencoded payload directly:\n\n```text\nif is_rfc7797_enabled(protected):\n if not payload_segment and payload:\n payload_segment = to_bytes(payload)\n payload = payload_segment\n```\n\nThe flattened JSON RFC7797 path has the same pattern:\n\n```text\npayload_segment = value[\"payload\"].encode(\"utf-8\")\nif is_rfc7797_enabled(member.headers()):\n payload = payload_segment\n```\n\nNeither branch calls `registry.validate_payload_size(payload_segment)` before accepting the unencoded payload.\n\n## Reproduction\n\nThe proof below uses only local Python APIs. It signs a payload one byte over the default limit and then compares normal JWS behavior with RFC7797 `b64=false` behavior.\n\nRequirements:\n\n```bash\npython -m pip install \"joserfc==1.6.5\"\n```\n\nRun:\n\n```bash\npython joserfc_rfc7797_size_bypass_poc.py\n```\n\nSelf-contained proof script:\n\n```python\n#!/usr/bin/env python3\nimport json\n\nimport joserfc\nfrom joserfc import jws\nfrom joserfc.jwk import OctKey\n\n\ndef check_compact(name, header, payload, key):\n token = jws.serialize_compact(header, payload, key)\n try:\n obj = jws.deserialize_compact(token, key)\n return {\n \"case\": name,\n \"accepted\": True,\n \"exception\": None,\n \"payload_len_after_deserialize\": len(obj.payload),\n }\n except Exception as exc:\n return {\n \"case\": name,\n \"accepted\": False,\n \"exception\": type(exc).__name__,\n \"error\": str(exc),\n }\n\n\ndef check_json(name, protected, payload, key):\n data = jws.serialize_json({\"protected\": protected}, payload, key)\n try:\n obj = jws.deserialize_json(data, key)\n return {\n \"case\": name,\n \"accepted\": True,\n \"exception\": None,\n \"payload_len_after_deserialize\": len(obj.payload),\n }\n except Exception as exc:\n return {\n \"case\": name,\n \"accepted\": False,\n \"exception\": type(exc).__name__,\n \"error\": str(exc),\n }\n\n\nkey = OctKey.import_key(\"secret-secret-secret\")\nlimit = jws.default_registry.max_payload_length\npayload = \"A\" * (limit + 1)\n\nresults = {\n \"joserfc_version\": joserfc.__version__,\n \"default_max_payload_length\": limit,\n \"payload_len\": len(payload),\n \"compact\": [\n check_compact(\"normal_b64_true\", {\"alg\": \"HS256\"}, payload, key),\n check_compact(\n \"rfc7797_b64_false\",\n {\"alg\": \"HS256\", \"b64\": False, \"crit\": [\"b64\"]},\n payload,\n key,\n ),\n ],\n \"json\": [\n check_json(\"normal_b64_true_json\", {\"alg\": \"HS256\"}, payload, key),\n check_json(\n \"rfc7797_b64_false_json\",\n {\"alg\": \"HS256\", \"b64\": False, \"crit\": [\"b64\"]},\n payload,\n key,\n ),\n ],\n}\nprint(json.dumps(results, indent=2, sort_keys=True))\n```\n\nExpected output on `1.6.5` includes:\n\n```json\n{\n \"default_max_payload_length\": 128000,\n \"payload_len\": 128001,\n \"compact\": [\n {\n \"case\": \"normal_b64_true\",\n \"accepted\": false,\n \"exception\": \"ExceededSizeError\"\n },\n {\n \"case\": \"rfc7797_b64_false\",\n \"accepted\": true,\n \"exception\": null,\n \"payload_len_after_deserialize\": 128001\n }\n ],\n \"json\": [\n {\n \"case\": \"normal_b64_true_json\",\n \"accepted\": false,\n \"exception\": \"ExceededSizeError\"\n },\n {\n \"case\": \"rfc7797_b64_false_json\",\n \"accepted\": true,\n \"exception\": null,\n \"payload_len_after_deserialize\": 128001\n }\n ]\n}\n```\n\n## Version Checks\n\nI reproduced the same differential behavior on these releases:\n\n| Version | Normal JWS over limit | RFC7797 `b64=false` over limit |\n| --- | --- | --- |\n| 1.3.4 | `ExceededSizeError` | accepted |\n| 1.3.5 | `ExceededSizeError` | accepted |\n| 1.4.2 | `ExceededSizeError` | accepted |\n| 1.6.2 | `ExceededSizeError` | accepted |\n| 1.6.3 | `ExceededSizeError` | accepted |\n| 1.6.4 | `ExceededSizeError` | accepted |\n| 1.6.5 | `ExceededSizeError` | accepted |\n\nThe exact earliest affected release may be broader. The versions above are the releases I directly tested where the JWS size-limit boundary exists and the RFC7797 path bypasses it.\n\n## Relationship to Existing Advisories\n\nI found two related public advisories for `joserfc`, but neither appears to cover this root cause.\n\n`GHSA-frfh-8v73-gjg4` / `CVE-2025-65015` describes oversized token parts being included in `ExceededSizeError` messages in older release ranges. The issue described here reproduces in `1.6.5` and is not about exception message content. The oversized RFC7797 payload is accepted instead of raising `ExceededSizeError`.\n\n`GHSA-w5r5-m38g-f9f9` / `CVE-2026-27932` describes unbounded PBES2 `p2c` iteration counts during JWE decryption. The issue described here is in JWS RFC7797 payload extraction and does not involve PBES2 or JWE decryption.\n\n## Workarounds\n\nBefore a fixed release is available, affected applications can reduce exposure by rejecting oversized serialized JWS inputs before passing them to `joserfc`, disabling or disallowing RFC7797 `b64=false` tokens if not needed, and enforcing strict request/header/body size limits at the application or reverse-proxy layer.\n\n## Suggested Remediation\n\nApply `registry.validate_payload_size(payload_segment)` to RFC7797 unencoded payloads before assigning them to the JWS object in both compact and flattened JSON extraction paths. Detached RFC7797 compact payloads supplied through the `payload` argument should be checked in the same way.",
"id": "GHSA-wphv-vfrh-23q5",
"modified": "2026-06-26T20:59:38Z",
"published": "2026-06-26T20:59:38Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/authlib/joserfc/security/advisories/GHSA-wphv-vfrh-23q5"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48990"
},
{
"type": "PACKAGE",
"url": "https://github.com/authlib/joserfc"
},
{
"type": "WEB",
"url": "https://github.com/authlib/joserfc/releases/tag/1.6.7"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
],
"summary": "joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization"
}
GHSA-WQ23-W7CM-HGG8
Vulnerability from github – Published: 2025-02-20 15:31 – Updated: 2025-11-04 21:31A lack of rate limiting in the 'Forgot Password', 'Email Settings' feature of PHPJabbers Car Park Booking System v3.0 allows attackers to send an excessive amount of email for a legitimate user, leading to a possible Denial of Service (DoS) via a large amount of generated e-mail messages.
{
"affected": [],
"aliases": [
"CVE-2023-51310"
],
"database_specific": {
"cwe_ids": [
"CWE-770"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-02-20T15:15:12Z",
"severity": "MODERATE"
},
"details": "A lack of rate limiting in the \u0027Forgot Password\u0027, \u0027Email Settings\u0027 feature of PHPJabbers Car Park Booking System v3.0 allows attackers to send an excessive amount of email for a legitimate user, leading to a possible Denial of Service (DoS) via a large amount of generated e-mail messages.",
"id": "GHSA-wq23-w7cm-hgg8",
"modified": "2025-11-04T21:31:30Z",
"published": "2025-02-20T15:31:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-51310"
},
{
"type": "WEB",
"url": "https://packetstorm.news/files/id/176492"
},
{
"type": "WEB",
"url": "https://www.phpjabbers.com/car-park-booking/#sectionDemo"
},
{
"type": "WEB",
"url": "http://packetstormsecurity.com/files/176492/PHPJabbers-Car-Park-Booking-System-3.0-Missing-Rate-Limiting.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L",
"type": "CVSS_V3"
}
]
}
Mitigation
Clearly specify the minimum and maximum expectations for capabilities, and dictate which behaviors are acceptable when resource allocation reaches limits.
Mitigation
Limit the amount of resources that are accessible to unprivileged users. Set per-user limits for resources. Allow the system administrator to define these limits. Be careful to avoid CWE-410.
Mitigation
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place, and it will help the administrator to identify who is committing the abuse. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
Mitigation MIT-5
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Mitigation MIT-15
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
Mitigation
- Mitigation of resource exhaustion attacks requires that the target system either:
- The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
- The second solution can be difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply requires more resources on the part of the attacker.
- recognizes the attack and denies that user further access for a given amount of time, typically by using increasing time delays
- uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Ensure that protocols have specific limits of scale placed on them.
Mitigation MIT-38.1
- If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery.
- Ensure that all failures in resource allocation place the system into a safe posture.
Mitigation MIT-47
Strategy: Resource Limitation
- Use quotas or other resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available. However, these functions are not available on all operating systems.
- When the current levels get close to the maximum that is defined for the application (see CWE-770), then limit the allocation of further resources to privileged users; alternately, begin releasing resources for less-privileged users. While this mitigation may protect the system from attack, it will not necessarily stop attackers from adversely impacting other users.
- Ensure that the application performs the appropriate error checks and error handling in case resources become unavailable (CWE-703).
CAPEC-125: Flooding
An adversary consumes the resources of a target by rapidly engaging in a large number of interactions with the target. This type of attack generally exposes a weakness in rate limiting or flow. When successful this attack prevents legitimate users from accessing the service and can cause the target to crash. This attack differs from resource depletion through leaks or allocations in that the latter attacks do not rely on the volume of requests made to the target but instead focus on manipulation of the target's operations. The key factor in a flooding attack is the number of requests the adversary can make in a given period of time. The greater this number, the more likely an attack is to succeed against a given target.
CAPEC-130: Excessive Allocation
An adversary causes the target to allocate excessive resources to servicing the attackers' request, thereby reducing the resources available for legitimate services and degrading or denying services. Usually, this attack focuses on memory allocation, but any finite resource on the target could be the attacked, including bandwidth, processing cycles, or other resources. This attack does not attempt to force this allocation through a large number of requests (that would be Resource Depletion through Flooding) but instead uses one or a small number of requests that are carefully formatted to force the target to allocate excessive resources to service this request(s). Often this attack takes advantage of a bug in the target to cause the target to allocate resources vastly beyond what would be needed for a normal request.
CAPEC-147: XML Ping of the Death
An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.
CAPEC-197: Exponential Data Expansion
An adversary submits data to a target application which contains nested exponential data expansion to produce excessively large output. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. However, this capability can be abused to create excessive demands on a processor's CPU and memory. A small number of nested expansions can result in an exponential growth in demands on memory.
CAPEC-229: Serialized Data Parameter Blowup
This attack exploits certain serialized data parsers (e.g., XML, YAML, etc.) which manage data in an inefficient manner. The attacker crafts an serialized data file with multiple configuration parameters in the same dataset. In a vulnerable parser, this results in a denial of service condition where CPU resources are exhausted because of the parsing algorithm. The weakness being exploited is tied to parser implementation and not language specific.
CAPEC-230: Serialized Data with Nested Payloads
Applications often need to transform data in and out of a data format (e.g., XML and YAML) by using a parser. It may be possible for an adversary to inject data that may have an adverse effect on the parser when it is being processed. Many data format languages allow the definition of macro-like structures that can be used to simplify the creation of complex structures. By nesting these structures, causing the data to be repeatedly substituted, an adversary can cause the parser to consume more resources while processing, causing excessive memory consumption and CPU utilization.
CAPEC-231: Oversized Serialized Data Payloads
An adversary injects oversized serialized data payloads into a parser during data processing to produce adverse effects upon the parser such as exhausting system resources and arbitrary code execution.
CAPEC-469: HTTP DoS
An attacker performs flooding at the HTTP level to bring down only a particular web application rather than anything listening on a TCP/IP connection. This denial of service attack requires substantially fewer packets to be sent which makes DoS harder to detect. This is an equivalent of SYN flood in HTTP. The idea is to keep the HTTP session alive indefinitely and then repeat that hundreds of times. This attack targets resource depletion weaknesses in web server software. The web server will wait to attacker's responses on the initiated HTTP sessions while the connection threads are being exhausted.
CAPEC-482: TCP Flood
An adversary may execute a flooding attack using the TCP protocol with the intent to deny legitimate users access to a service. These attacks exploit the weakness within the TCP protocol where there is some state information for the connection the server needs to maintain. This often involves the use of TCP SYN messages.
CAPEC-486: UDP Flood
An adversary may execute a flooding attack using the UDP protocol with the intent to deny legitimate users access to a service by consuming the available network bandwidth. Additionally, firewalls often open a port for each UDP connection destined for a service with an open UDP port, meaning the firewalls in essence save the connection state thus the high packet nature of a UDP flood can also overwhelm resources allocated to the firewall. UDP attacks can also target services like DNS or VoIP which utilize these protocols. Additionally, due to the session-less nature of the UDP protocol, the source of a packet is easily spoofed making it difficult to find the source of the attack.
CAPEC-487: ICMP Flood
An adversary may execute a flooding attack using the ICMP protocol with the intent to deny legitimate users access to a service by consuming the available network bandwidth. A typical attack involves a victim server receiving ICMP packets at a high rate from a wide range of source addresses. Additionally, due to the session-less nature of the ICMP protocol, the source of a packet is easily spoofed making it difficult to find the source of the attack.
CAPEC-488: HTTP Flood
An adversary may execute a flooding attack using the HTTP protocol with the intent to deny legitimate users access to a service by consuming resources at the application layer such as web services and their infrastructure. These attacks use legitimate session-based HTTP GET requests designed to consume large amounts of a server's resources. Since these are legitimate sessions this attack is very difficult to detect.
CAPEC-489: SSL Flood
An adversary may execute a flooding attack using the SSL protocol with the intent to deny legitimate users access to a service by consuming all the available resources on the server side. These attacks take advantage of the asymmetric relationship between the processing power used by the client and the processing power used by the server to create a secure connection. In this manner the attacker can make a large number of HTTPS requests on a low provisioned machine to tie up a disproportionately large number of resources on the server. The clients then continue to keep renegotiating the SSL connection. When multiplied by a large number of attacking machines, this attack can result in a crash or loss of service to legitimate users.
CAPEC-490: Amplification
An adversary may execute an amplification where the size of a response is far greater than that of the request that generates it. The goal of this attack is to use a relatively few resources to create a large amount of traffic against a target server. To execute this attack, an adversary send a request to a 3rd party service, spoofing the source address to be that of the target server. The larger response that is generated by the 3rd party service is then sent to the target server. By sending a large number of initial requests, the adversary can generate a tremendous amount of traffic directed at the target. The greater the discrepancy in size between the initial request and the final payload delivered to the target increased the effectiveness of this attack.
CAPEC-491: Quadratic Data Expansion
An adversary exploits macro-like substitution to cause a denial of service situation due to excessive memory being allocated to fully expand the data. The result of this denial of service could cause the application to freeze or crash. This involves defining a very large entity and using it multiple times in a single entity substitution. CAPEC-197 is a similar attack pattern, but it is easier to discover and defend against. This attack pattern does not perform multi-level substitution and therefore does not obviously appear to consume extensive resources.
CAPEC-493: SOAP Array Blowup
An adversary may execute an attack on a web service that uses SOAP messages in communication. By sending a very large SOAP array declaration to the web service, the attacker forces the web service to allocate space for the array elements before they are parsed by the XML parser. The attacker message is typically small in size containing a large array declaration of say 1,000,000 elements and a couple of array elements. This attack targets exhaustion of the memory resources of the web service.
CAPEC-494: TCP Fragmentation
An adversary may execute a TCP Fragmentation attack against a target with the intention of avoiding filtering rules of network controls, by attempting to fragment the TCP packet such that the headers flag field is pushed into the second fragment which typically is not filtered.
CAPEC-495: UDP Fragmentation
An attacker may execute a UDP Fragmentation attack against a target server in an attempt to consume resources such as bandwidth and CPU. IP fragmentation occurs when an IP datagram is larger than the MTU of the route the datagram has to traverse. Typically the attacker will use large UDP packets over 1500 bytes of data which forces fragmentation as ethernet MTU is 1500 bytes. This attack is a variation on a typical UDP flood but it enables more network bandwidth to be consumed with fewer packets. Additionally it has the potential to consume server CPU resources and fill memory buffers associated with the processing and reassembling of fragmented packets.
CAPEC-496: ICMP Fragmentation
An attacker may execute a ICMP Fragmentation attack against a target with the intention of consuming resources or causing a crash. The attacker crafts a large number of identical fragmented IP packets containing a portion of a fragmented ICMP message. The attacker these sends these messages to a target host which causes the host to become non-responsive. Another vector may be sending a fragmented ICMP message to a target host with incorrect sizes in the header which causes the host to hang.
CAPEC-528: XML Flood
An adversary may execute a flooding attack using XML messages with the intent to deny legitimate users access to a web service. These attacks are accomplished by sending a large number of XML based requests and letting the service attempt to parse each one. In many cases this type of an attack will result in a XML Denial of Service (XDoS) due to an application becoming unstable, freezing, or crashing.