CVE-2017-13720

Severity: high (CVSS 7.1 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2017-10-11 · updated 2026-06-17
Weakness: CWE-125

Description

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 '\0' characters are incorrectly skipped in situations involving ? characters.

Affected products

X.Org Libxfont: through 1.5.2; 2.0.0, 2.0.1

References

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
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

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