جزئیات آسیب‌پذیری

pyasn1 is a generic ASN.1 library for Python. From 0.3.3 until 0.6.5, schemaless container decoding stores every decoded component's TagSet in a growing set even though only one-versus-multiple tag types must be distinguished. Attacker-controlled BER, CER, or DER input contains many distinct long tag IDs whose TagSet hashes collide. Each later set insertion compares against an increasing number of earlier colliding tags in ConstructedPayloadDecoderBase._decodeComponentsSchemaless, producing quadratic CPU work while decoded values and order remain valid. Repeated inputs can exhaust decoder CPU and reduce service availability. This issue is fixed in version 0.6.5.

• https://github.com/pyasn1/pyasn1/pull/132 x_refsource_MISC
• https://github.com/pyasn1/pyasn1/commit/a36e3a3d067148d26197a6b7221fd0e2cde9cc86 x_refsource_MISC
• https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5 x_refsource_MISC
• https://github.com/pyasn1/pyasn1/security/advisories/GHSA-fm9c-5rcf-2q5p x_refsource_CONFIRM