- Description
- Expat through 2.8.3 contains a denial of service vulnerability caused by quadratic algorithmic complexity in the storeAtts() function in xmlparse.c, where processing N specified attributes with non-normalized values triggers an O(N^2) linear scan of elementType->defaultAtts to determine CDATA status. A remote unauthenticated attacker can supply a single well-formed XML document of a few megabytes to an application parsing untrusted XML to cause excessive CPU consumption, resulting in denial of service without requiring authentication, external entity resolution, or non-default parser options.
- Source
- disclosure@vulncheck.com
- NVD status
- Analyzed
- Products
- libexpat
CVSS 4.0
- Type
- Secondary
- Base score
- 8.7
- Impact score
- -
- Exploitability score
- -
- Vector string
- 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: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
- Severity
- HIGH
CVSS 3.1
- Type
- Secondary
- Base score
- 7.5
- Impact score
- 3.6
- Exploitability score
- 3.9
- Vector string
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Severity
- HIGH
- disclosure@vulncheck.com
- CWE-407
- Hype score
- Not currently trending
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"criteria": "cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*",
"matchCriteriaId": "451AFC5E-7991-4082-8CB4-C14E708CA99A",
"versionEndIncluding": "2.8.3",
"vulnerable": true
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"operator": "OR"
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]