pypdf is a free and open-source pure-python PDF library. Prior to 6.21.2, an incomplete remediation for repeated malformed cross-reference entries in GHSA-55h5-xmcq-c37v could still trigger a complete PDF stream reload during each recovery attempt even when a recovery cache was present, causing crafted cross-reference streams to produce long runtimes. This issue is fixed in version 6.21.2.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/py-pdf/pypdf/commit/68a0e5046cc9e14a6c24a21a713f3c7fbde18b4b
security-advisories@github.com
https://github.com/py-pdf/pypdf/pull/4240
security-advisories@github.com
https://github.com/py-pdf/pypdf/releases/tag/6.21.2
security-advisories@github.com
https://github.com/py-pdf/pypdf/security/advisories/GHSA-jr96-gvgh-j3r4
security-advisories@github.com