CWE-400
DiscouragedUncontrolled Resource Consumption
Abstraction: Class · Status: Draft
The product does not properly control the allocation and maintenance of a limited resource.
5412 vulnerabilities reference this CWE, most recent first.
GHSA-X7HP-R3QG-R3CJ
Vulnerability from github – Published: 2026-02-26 19:55 – Updated: 2026-02-26 19:55Impact
An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the xfa property of a reader or writer and the corresponding stream being compressed using /FlateDecode.
Patches
This has been fixed in pypdf==6.7.3.
Workarounds
If projects cannot upgrade yet, consider applying the changes from PR #3658.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "pypdf"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "6.7.3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-27888"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-26T19:55:33Z",
"nvd_published_at": "2026-02-26T01:16:25Z",
"severity": "MODERATE"
},
"details": "### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`.\n\n### Patches\nThis has been fixed in [pypdf==6.7.3](https://github.com/py-pdf/pypdf/releases/tag/6.7.3).\n\n### Workarounds\nIf projects cannot upgrade yet, consider applying the changes from PR [#3658](https://github.com/py-pdf/pypdf/pull/3658).",
"id": "GHSA-x7hp-r3qg-r3cj",
"modified": "2026-02-26T19:55:33Z",
"published": "2026-02-26T19:55:33Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/security/advisories/GHSA-x7hp-r3qg-r3cj"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27888"
},
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/pull/3658"
},
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/commit/7a4c8246ed48d9d328fb596942271da47b6d109c"
},
{
"type": "PACKAGE",
"url": "https://github.com/py-pdf/pypdf"
},
{
"type": "WEB",
"url": "https://github.com/py-pdf/pypdf/releases/tag/6.7.3"
}
],
"schema_version": "1.4.0",
"severity": [
{
"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/E:U",
"type": "CVSS_V4"
}
],
"summary": "pypdf: Manipulated FlateDecode XFA streams can exhaust RAM"
}
GHSA-X7PH-QCHV-4QV7
Vulnerability from github – Published: 2023-02-01 18:30 – Updated: 2023-02-10 00:30On versions 17.0.x before 17.0.0.2, 16.1.x before 16.1.3.3, 15.1.0 before 15.1.8, 14.1.x before 14.1.5.3, and all versions of 13.1.x, when a BIG-IP Advanced WAF or BIG-IP ASM security policy is configured on a virtual server, undisclosed requests can cause an increase in memory resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
{
"affected": [],
"aliases": [
"CVE-2023-23552"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-02-01T18:15:00Z",
"severity": "HIGH"
},
"details": "On versions 17.0.x before 17.0.0.2, 16.1.x before 16.1.3.3, 15.1.0 before 15.1.8, 14.1.x before 14.1.5.3, and all versions of 13.1.x, when a BIG-IP Advanced WAF or BIG-IP ASM security policy is configured on a virtual server, undisclosed requests can cause an increase in memory resource utilization. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
"id": "GHSA-x7ph-qchv-4qv7",
"modified": "2023-02-10T00:30:20Z",
"published": "2023-02-01T18:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-23552"
},
{
"type": "WEB",
"url": "https://my.f5.com/manage/s/article/K17542533"
}
],
"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-X86Q-VGV7-R385
Vulnerability from github – Published: 2025-04-28 15:31 – Updated: 2025-04-28 15:31The multiScan and picoScan are vulnerable to a denial-of-service (DoS) attack. A remote attacker can exploit this vulnerability by conducting a Slowloris-type attack, causing the web page to become unresponsive.
{
"affected": [],
"aliases": [
"CVE-2025-32472"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-04-28T13:15:23Z",
"severity": "MODERATE"
},
"details": "The multiScan and picoScan are vulnerable to a denial-of-service (DoS) attack. A remote attacker can exploit this vulnerability by conducting a Slowloris-type attack, causing the web page to become unresponsive.",
"id": "GHSA-x86q-vgv7-r385",
"modified": "2025-04-28T15:31:41Z",
"published": "2025-04-28T15:31:41Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-32472"
},
{
"type": "WEB",
"url": "https://cdn.sick.com/media/docs/1/11/411/Special_information_CYBERSECURITY_BY_SICK_en_IM0084411.PDF"
},
{
"type": "WEB",
"url": "https://sick.com/psirt"
},
{
"type": "WEB",
"url": "https://www.cisa.gov/resources-tools/resources/ics-recommended-practices"
},
{
"type": "WEB",
"url": "https://www.first.org/cvss/calculator/3.1"
},
{
"type": "WEB",
"url": "https://www.sick.com/.well-known/csaf/white/2025/sca-2025-0006.json"
},
{
"type": "WEB",
"url": "https://www.sick.com/.well-known/csaf/white/2025/sca-2025-0006.pdf"
}
],
"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"
}
]
}
GHSA-X878-48G9-62P4
Vulnerability from github – Published: 2026-04-21 21:31 – Updated: 2026-04-21 21:31Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).
{
"affected": [],
"aliases": [
"CVE-2026-21998"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-21T21:16:24Z",
"severity": "MODERATE"
},
"details": "Vulnerability in the MySQL Server product of Oracle MySQL (component: Server: Optimizer). Supported versions that are affected are 8.0.0-8.0.45, 8.4.0-8.4.8 and 9.0.0-9.6.0. Easily exploitable vulnerability allows high privileged attacker with network access via multiple protocols to compromise MySQL Server. Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of MySQL Server. CVSS 3.1 Base Score 4.9 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H).",
"id": "GHSA-x878-48g9-62p4",
"modified": "2026-04-21T21:31:24Z",
"published": "2026-04-21T21:31:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-21998"
},
{
"type": "WEB",
"url": "https://www.oracle.com/security-alerts/cpuapr2026.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-X8CF-FRRM-7GFX
Vulnerability from github – Published: 2023-09-06 03:30 – Updated: 2024-04-04 07:29A denial-of-service issue was addressed with improved input validation. This issue is fixed in macOS Ventura 13.3. A remote user may be able to cause a denial-of-service.
{
"affected": [],
"aliases": [
"CVE-2023-28188"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-09-06T02:15:08Z",
"severity": "MODERATE"
},
"details": "A denial-of-service issue was addressed with improved input validation. This issue is fixed in macOS Ventura 13.3. A remote user may be able to cause a denial-of-service.",
"id": "GHSA-x8cf-frrm-7gfx",
"modified": "2024-04-04T07:29:57Z",
"published": "2023-09-06T03:30:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-28188"
},
{
"type": "WEB",
"url": "https://support.apple.com/en-us/HT213670"
},
{
"type": "WEB",
"url": "https://support.apple.com/kb/HT213670"
}
],
"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-X8CG-FQ8G-MXFX
Vulnerability from github – Published: 2026-04-02 19:07 – Updated: 2026-05-13 15:21Summary
Rack::Utils.get_byte_ranges parses the HTTP Range header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the file size, it does not restrict the count of ranges. An attacker can supply many small overlapping ranges such as 0-0,0-0,0-0,... to trigger disproportionate CPU, memory, I/O, and bandwidth consumption per request.
This results in a denial of service condition in Rack file-serving paths that process multipart byte range responses.
Details
Rack::Utils.get_byte_ranges accepts a comma-separated list of byte ranges and validates them based on their aggregate size, but does not impose a limit on how many individual ranges may be supplied.
As a result, a request such as:
Range: bytes=0-0,0-0,0-0,0-0,...
can contain thousands of overlapping one-byte ranges while still satisfying the total-size check added for CVE-2024-26141.
When such a header is processed by Rack’s file-serving code, each range causes additional work, including multipart response generation, per-range iteration, file seek and read operations, and temporary string allocation for response size calculation and output. This allows a relatively small request header to trigger disproportionately expensive processing and a much larger multipart response.
The issue is distinct from CVE-2024-26141. That fix prevents range sets whose total byte coverage exceeds the file size, but does not prevent a large number of overlapping ranges whose summed size remains within that limit.
Impact
Applications that expose file-serving paths with byte range support may be vulnerable to denial of service.
An unauthenticated attacker can send crafted Range headers containing many small overlapping ranges to consume excessive CPU time, memory, file I/O, and bandwidth. Repeated requests may reduce application availability and increase pressure on workers and garbage collection.
Mitigation
- Update to a patched version of Rack that limits the number of accepted byte ranges.
- Reject or normalize multipart byte range requests containing excessive range counts.
- Consider disabling multipart range support where it is not required.
- Apply request filtering or header restrictions at the reverse proxy or application boundary to limit abusive
Rangeheaders.
{
"affected": [
{
"package": {
"ecosystem": "RubyGems",
"name": "rack"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.2.23"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "RubyGems",
"name": "rack"
},
"ranges": [
{
"events": [
{
"introduced": "3.0.0.beta1"
},
{
"fixed": "3.1.21"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "RubyGems",
"name": "rack"
},
"ranges": [
{
"events": [
{
"introduced": "3.2.0"
},
{
"fixed": "3.2.6"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-34826"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-02T19:07:28Z",
"nvd_published_at": "2026-04-02T17:16:25Z",
"severity": "MODERATE"
},
"details": "## Summary\n\n`Rack::Utils.get_byte_ranges` parses the HTTP `Range` header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the file size, it does not restrict the count of ranges. An attacker can supply many small overlapping ranges such as `0-0,0-0,0-0,...` to trigger disproportionate CPU, memory, I/O, and bandwidth consumption per request.\n\nThis results in a denial of service condition in Rack file-serving paths that process multipart byte range responses.\n\n## Details\n\n`Rack::Utils.get_byte_ranges` accepts a comma-separated list of byte ranges and validates them based on their aggregate size, but does not impose a limit on how many individual ranges may be supplied.\n\nAs a result, a request such as:\n\n```http\nRange: bytes=0-0,0-0,0-0,0-0,...\n```\n\ncan contain thousands of overlapping one-byte ranges while still satisfying the total-size check added for CVE-2024-26141.\n\nWhen such a header is processed by Rack\u2019s file-serving code, each range causes additional work, including multipart response generation, per-range iteration, file seek and read operations, and temporary string allocation for response size calculation and output. This allows a relatively small request header to trigger disproportionately expensive processing and a much larger multipart response.\n\nThe issue is distinct from CVE-2024-26141. That fix prevents range sets whose total byte coverage exceeds the file size, but does not prevent a large number of overlapping ranges whose summed size remains within that limit.\n\n## Impact\n\nApplications that expose file-serving paths with byte range support may be vulnerable to denial of service.\n\nAn unauthenticated attacker can send crafted `Range` headers containing many small overlapping ranges to consume excessive CPU time, memory, file I/O, and bandwidth. Repeated requests may reduce application availability and increase pressure on workers and garbage collection.\n\n## Mitigation\n\n* Update to a patched version of Rack that limits the number of accepted byte ranges.\n* Reject or normalize multipart byte range requests containing excessive range counts.\n* Consider disabling multipart range support where it is not required.\n* Apply request filtering or header restrictions at the reverse proxy or application boundary to limit abusive `Range` headers.",
"id": "GHSA-x8cg-fq8g-mxfx",
"modified": "2026-05-13T15:21:07Z",
"published": "2026-04-02T19:07:28Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/rack/rack/security/advisories/GHSA-x8cg-fq8g-mxfx"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34826"
},
{
"type": "PACKAGE",
"url": "https://github.com/rack/rack"
},
{
"type": "WEB",
"url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34826.yml"
}
],
"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": "Rack\u0027s multipart byte range processing allows denial of service via excessive overlapping ranges"
}
GHSA-X8FM-G4F5-MXFV
Vulnerability from github – Published: 2022-05-24 19:02 – Updated: 2022-05-24 19:02An issue was discovered in Prosody before 0.11.9. Default settings are susceptible to remote unauthenticated denial-of-service (DoS) attacks via memory exhaustion when running under Lua 5.2 or Lua 5.3.
{
"affected": [],
"aliases": [
"CVE-2021-32918"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2021-05-13T16:15:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in Prosody before 0.11.9. Default settings are susceptible to remote unauthenticated denial-of-service (DoS) attacks via memory exhaustion when running under Lua 5.2 or Lua 5.3.",
"id": "GHSA-x8fm-g4f5-mxfv",
"modified": "2022-05-24T19:02:20Z",
"published": "2022-05-24T19:02:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32918"
},
{
"type": "WEB",
"url": "https://blog.prosody.im/prosody-0.11.9-released"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/6MFFBZWXKPZEVZNQSVJNCUE7WRF3T7DG"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GUN63AHEWB2WRROJHU3BVJRWLONCT2B7"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LWJ2DG2DFJOEFEWOUN26IMYYWGSA2ZEE"
},
{
"type": "WEB",
"url": "https://security.gentoo.org/glsa/202105-15"
},
{
"type": "WEB",
"url": "https://www.debian.org/security/2021/dsa-4916"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/05/13/1"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2021/05/14/2"
}
],
"schema_version": "1.4.0",
"severity": []
}
GHSA-X8MX-XG8R-CGWP
Vulnerability from github – Published: 2023-04-20 15:30 – Updated: 2024-04-04 03:36An issue was discovered in ONOS 2.5.1. The purge-requested intent remains on the list, but it does not respond to changes in topology (e.g., link failure). In combination with other applications, it could lead to a failure of network management.
{
"affected": [],
"aliases": [
"CVE-2022-24035"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-04-20T13:15:06Z",
"severity": "HIGH"
},
"details": "An issue was discovered in ONOS 2.5.1. The purge-requested intent remains on the list, but it does not respond to changes in topology (e.g., link failure). In combination with other applications, it could lead to a failure of network management.",
"id": "GHSA-x8mx-xg8r-cgwp",
"modified": "2024-04-04T03:36:44Z",
"published": "2023-04-20T15:30:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-24035"
},
{
"type": "WEB",
"url": "https://wiki.onosproject.org/display/ONOS/Intent+Framework"
},
{
"type": "WEB",
"url": "https://www.usenix.org/system/files/sec23fall-prepub-285_kim-jiwon.pdf"
}
],
"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-X94C-JR4G-FFPM
Vulnerability from github – Published: 2024-07-09 18:30 – Updated: 2024-07-09 18:30Windows Online Certificate Status Protocol (OCSP) Server Denial of Service Vulnerability
{
"affected": [],
"aliases": [
"CVE-2024-38067"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-09T17:15:39Z",
"severity": "HIGH"
},
"details": "Windows Online Certificate Status Protocol (OCSP) Server Denial of Service Vulnerability",
"id": "GHSA-x94c-jr4g-ffpm",
"modified": "2024-07-09T18:30:52Z",
"published": "2024-07-09T18:30:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-38067"
},
{
"type": "WEB",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-38067"
}
],
"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-X977-8678-7C9X
Vulnerability from github – Published: 2022-05-13 01:34 – Updated: 2022-05-13 01:34Rockwell Automation RSLinx Classic Versions 4.00.01 and prior. A remote, unauthenticated threat actor may intentionally send specially crafted Ethernet/IP packets to Port 44818, causing the software application to stop responding and crash. The user must restart the software to regain functionality.
{
"affected": [],
"aliases": [
"CVE-2018-14827"
],
"database_specific": {
"cwe_ids": [
"CWE-400"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-09-20T19:29:00Z",
"severity": "HIGH"
},
"details": "Rockwell Automation RSLinx Classic Versions 4.00.01 and prior. A remote, unauthenticated threat actor may intentionally send specially crafted Ethernet/IP packets to Port 44818, causing the software application to stop responding and crash. The user must restart the software to regain functionality.",
"id": "GHSA-x977-8678-7c9x",
"modified": "2022-05-13T01:34:24Z",
"published": "2022-05-13T01:34:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-14827"
},
{
"type": "WEB",
"url": "https://ics-cert.us-cert.gov/advisories/ICSA-18-263-02"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
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. 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
- 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 is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- recognizes the attack and denies that user further access for a given amount of time, or
- 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
Ensure that all failures in resource allocation place the system into a safe posture.
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-227: Sustained Client Engagement
An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.
CAPEC-492: Regular Expression Exponential Blowup
An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.