PT-2020-2074 · Mit+1 · Pam Krb5+1
Russ Allbery
·
Published
2020-03-31
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Updated
2020-04-04
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CVE-2020-10595
CVSS v3.1
9.8
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
pam-krb5 versions prior to 4.9
Description
The issue is related to a buffer overflow in pam-krb5 that may cause remote code execution when the Kerberos library performs supplemental prompting. This can happen if an attacker responds to a prompt with a carefully chosen answer length, potentially overflowing a buffer provided by the underlying Kerberos library. The effect can range from heap corruption to stack corruption, with possible code execution. This code path is used when the Kerberos library does supplemental prompting, such as with PKINIT or the non-standard no prompt PAM configuration option.
Recommendations
For versions prior to 4.9, update to version 4.9 or later to resolve the issue. As a temporary workaround, consider disabling supplemental prompting by the Kerberos library until a patch is available. Restrict access to the pam-krb5 library to minimize the risk of exploitation. Avoid using the non-standard no prompt PAM configuration option until the issue is resolved.
Fix
RCE
Buffer Overflow
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Weakness Enumeration
Related Identifiers
Affected Products
Ubuntu
Pam Krb5