CVE-2019-12529 Information

Description

An issue was discovered in Squid 2.x through 2.7.STABLE9 3.x through 3.5.28 and 4.x through 4.7. When Squid is configured to use Basic Authentication the Proxy-Authorization header is parsed via uudecode. uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The length is then used to start decoding the string. There are no checks to ensure that the length it calculates isn’t greater than the input buffer. This leads to adjacent memory being decoded as well. An attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the display of usernames on error pages.

CVSS Vector

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Reference

http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00053.html http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00056.html http://www.squid-cache.org/Versions/v4/changesets/ http://www.squid-cache.org/Versions/v4/changesets/squid-4-dd46b5417809647f561d8a5e0e74c3aacd235258.patch https://github.com/squid-cache/squid/commits/v4 https://lists.debian.org/debian-lts-announce/2019/07/msg00018.html https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html https://lists.fedoraproject.org/archives/list/[email protected]/message/SPXN2CLAGN5QSQBTOV5IGVLDOQSRFNTZ/ https://seclists.org/bugtraq/2019/Aug/42 https://usn.ubuntu.com/4065-1/ https://usn.ubuntu.com/4065-2/ https://www.debian.org/security/2019/dsa-4507

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

5.9