SB2020111617 - Denial of service in MIT Kerberos 5
Published: November 16, 2020 Updated: November 18, 2020
Security Bulletin ID
SB2020111617
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Uncontrolled Recursion (CVE-ID: CVE-2020-28196)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to uncontrolled recursion in MIT Kerberos 5 (aka krb5) implementation when processing ASN.1-encoded Kerberos messages in lib/krb5/asn.1/asn1_encode.c. A remote attacker can pass specially crafted data to the application that uses Kerberos and perform a denial of service (DoS) attack.
Remediation
Install update from vendor's website.
References
- https://github.com/krb5/krb5/commit/57415dda6cf04e73ffc3723be518eddfae599bfd
- https://lists.debian.org/debian-lts-announce/2020/11/msg00011.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/73IGOG6CZAVMVNS4GGRMOLOZ7B6QVA7F/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KPH2V3WSQTELROZK3GFCPQDOFLKIZ6H5/
- https://security.gentoo.org/glsa/202011-17