CVE-2010-4020: Mit Kerberos 5

Medium severity, CVSS 6.3. EPSS: 1.9% chance of exploitation in the next 30 days.

MIT Kerberos 5 (aka krb5) 1.8.x through 1.8.3 does not reject RC4 key-derivation checksums, which might allow remote authenticated users to forge a (1) AD-SIGNEDPATH or (2) AD-KDC-ISSUED signature, and possibly gain privileges, by leveraging the small key space that results from certain one-byte stream-cipher operations.

Affected products

• Mit Kerberos 5: version 1.8 only; version 1.8.1 only; version 1.8.2 only; version 1.8.3 only

Published 2010-12-02. Last modified 2026-06-16.