CVE-2024-39312: Botan has an Authorization Error due to Name Constraint Decoding Bug

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-08 · updated 2026-06-17
Weakness: CWE-295

Description

Botan is a C++ cryptography library. X.509 certificates can identify elliptic curves using either an object identifier or using explicit encoding of the parameters. A bug in the parsing of name constraint extensions in X.509 certificates meant that if the extension included both permitted subtrees and excluded subtrees, only the permitted subtree would be checked. If a certificate included a name which was permitted by the permitted subtree but also excluded by excluded subtree, it would be accepted. Fixed in versions 3.5.0 and 2.19.5.

Affected products

randombit botan: before 2.19.5; from 3.0.0 before 3.5.0 — fixed in 2.19.5, 3.5.0

How to fix

Upgrade to a fixed version: randombit botan 2.19.5, 3.5.0. Check the vendor advisory for mitigations.

References

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