CVE-2020-10595

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-03-31 · updated 2026-06-17
Weakness: CWE-120

Description

pam-krb5 before 4.9 has a buffer overflow that might cause remote code execution in situations involving supplemental prompting by a Kerberos library. It may overflow a buffer provided by the underlying Kerberos library by a single '\0' byte if an attacker responds to a prompt with an answer of a carefully chosen length. The effect may range from heap corruption to stack corruption depending on the structure of the underlying Kerberos library, with unknown effects but possibly including code execution. This code path is not used for normal authentication, but only when the Kerberos library does supplemental prompting, such as with PKINIT or when using the non-standard no_prompt PAM configuration option.

Affected products

Debian Linux: 8.0, 9.0, 10.0
Pam-Krb5 Project Pam-Krb5: before 4.9 — fixed in 4.9

How to fix

Upgrade to a fixed version: Pam-Krb5 Project Pam-Krb5 4.9. Check the vendor advisory for mitigations.

References

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