SB2023012558 - Ubuntu update for krb5



SB2023012558 - Ubuntu update for krb5

Published: January 25, 2023

Security Bulletin ID SB2023012558
Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Reachable Assertion (CVE-ID: CVE-2018-20217)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a reachable assertion in in the KDC. A remote attacker can obtain a krbtgt ticket using an older encryption type (single-DES, triple-DES, or RC4) and crash the KDC by making an S4U2Self request.


2) Integer overflow (CVE-ID: CVE-2022-42898)

The vulnerability allows a remote user to execute arbitrary code on the target system.

The vulnerability exists due to an integer overflow within the S4U2Proxy handler on 32-bit systems. A remote user can send specially crafted request to the KDC server, trigger an integer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Remediation

Install update from vendor's website.