CVE-2020-10595
pam-krb5 before 4.9 has a buffer overflow that might cause remote code execution in situations...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
9.8
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.
- Record
CVE-2020-10595- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-120
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2020-10595- Updated
- 2026-11-02
EUVDEUVD-2020-3044 No score
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.
- Record
EUVD-2020-3044- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-63wp-w3mg-whpq No score
pam-krb5 before 4.9 has a buffer overflow that might cause remote code execution in situations...
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.
- Record
GHSA-63wp-w3mg-whpq- Updated
- 2026-11-02
OSV
9.8
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.
- Record
CVE-2020-10595- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2020-10595
9.8
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.
- Record
DEBIAN-CVE-2020-10595- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2020-10595
9.8
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.
- Record
UBUNTU-CVE-2020-10595- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVUSN-4314-1 No score
libpam-krb5 vulnerability
Russ Allbery discovered that pam-krb5 incorrectly handled some responses. An attacker could possibly use this issue to execute arbitrary code.
- Record
USN-4314-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libpam-krb5Debian:12 |
before 4.9-1 | 4.9-1 |
libpam-krb5Debian:13 |
before 4.9-1 | 4.9-1 |
libpam-krb5Debian:14 |
before 4.9-1 | 4.9-1 |
libpam-krb5Debian:8 |
before 4.6-3+deb8u1, plus listed versions 4.6-3 |
4.6-3+deb8u1 |
libpam-krb5Debian:9 |
before 4.7-4+deb9u1, plus listed versions 4.7-4 |
4.7-4+deb9u1 |
libpam-krb5Debian:10 |
before 4.8-2+deb10u1, plus listed versions 4.8-2 |
4.8-2+deb10u1 |
libpam-krb5Ubuntu:Pro:14.04:LTS |
before 4.6-2ubuntu0.1~esm1, plus listed versions 4.6-2 |
4.6-2ubuntu0.1~esm1 |
libpam-krb5Ubuntu:16.04:LTS |
before 4.7-2ubuntu0.1, plus listed versions 4.7-2 |
4.7-2ubuntu0.1 |
libpam-krb5Ubuntu:18.04:LTS |
before 4.8-1ubuntu0.1, plus listed versions 4.7-44.8-1 |
4.8-1ubuntu0.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2020-10595 is a critical vulnerability (CVSS 9.8) in Pam-krb5 Project Pam-krb5, published March 31, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 4.78%, the 91st percentile. Fixed in libpam-krb5 4.9-1.