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.
References (12)
Core 12
Core References
Vendor Advisory x_refsource_confirm
http://www.squid-cache.org/Versions/v4/changesets/
Patch, Third Party Advisory x_refsource_confirm
https://github.com/squid-cache/squid/commits/v4
Patch, Vendor Advisory x_refsource_confirm
http://www.squid-cache.org/Versions/v4/changesets/squid-4-dd46b5417809647f561d8a5e0e74c3aacd235258.patch
Third Party Advisory vendor-advisory
x_refsource_ubuntu
https://usn.ubuntu.com/4065-1/
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2019/07/msg00018.html
Third Party Advisory vendor-advisory
x_refsource_ubuntu
https://usn.ubuntu.com/4065-2/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPXN2CLAGN5QSQBTOV5IGVLDOQSRFNTZ/
Third Party Advisory vendor-advisory
x_refsource_debian
https://www.debian.org/security/2019/dsa-4507
Mailing List, Third Party Advisory mailing-list
x_refsource_bugtraq
https://seclists.org/bugtraq/2019/Aug/42
Mailing List, Third Party Advisory vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00053.html
Mailing List, Third Party Advisory vendor-advisory
x_refsource_suse
http://lists.opensuse.org/opensuse-security-announce/2019-11/msg00056.html
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/07/msg00009.html
Scores
CVSS v3
5.9
EPSS
0.1596
EPSS Percentile
94.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Details
CWE
CWE-125
Status
published
Products (12)
canonical/ubuntu_linux
12.04
canonical/ubuntu_linux
16.04
canonical/ubuntu_linux
18.04
canonical/ubuntu_linux
19.04
debian/debian_linux
8.0
debian/debian_linux
9.0
debian/debian_linux
10.0
fedoraproject/fedora
29
opensuse/leap
15.0
opensuse/leap
15.1
... and 2 more
Published
Jul 11, 2019
Tracked Since
Feb 18, 2026