Description
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.
Problem types
CWE-400: Uncontrolled Resource Consumption
Product status
References
github.com/...pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j
github.com/...ommit/628e36ecbb5277a3f01572ce418ef54271b165a5
github.com/pyasn1/pyasn1/releases/tag/v0.6.4