Out-of-bounds read in libXfont - CVE-2017-13720
Published: October 11, 2017 / Updated: August 8, 2020
Vulnerability identifier: #VU38075
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2017-13720
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: X.org
Affected software:
libXfont
libXfont
Detailed vulnerability description
The vulnerability allows a local authenticated user to #BASIC_IMPACT#.
In the PatternMatch function in fontfile/fontdir.c in libXfont through 1.5.2 and 2.x before 2.0.2, an attacker with access to an X connection can cause a buffer over-read during pattern matching of fonts, leading to information disclosure or a crash (denial of service). This occurs because ' ' characters are incorrectly skipped in situations involving ? characters.
How to mitigate CVE-2017-13720
Install update from vendor's website.
Sources
- http://www.debian.org/security/2017/dsa-3995
- https://bugzilla.redhat.com/show_bug.cgi?id=1500690
- https://bugzilla.suse.com/show_bug.cgi?id=1054285
- https://cgit.freedesktop.org/xorg/lib/libXfont/commit/?id=d1e670a4a8704b8708e493ab6155589bcd570608
- https://security.gentoo.org/glsa/201711-08
- https://www.x.org/releases/individual/lib/libXfont2-2.0.2.tar.bz2