High
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2017-13720
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 09:51 UTC · Revision 1
Source evidence
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.
osv:CVE-2017-13720
Complete source record
{
"id": "a88caf296ea8ff480c92220d3d403c8a8bea06c98cc0abb2d57fd50a201a92f2",
"url": "https://osv.dev/vulnerability/CVE-2017-13720",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2017-13720",
"summary": "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.",
"evidence": "osv:CVE-2017-13720",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2017-13720",
"aliases": [
"CVE-2017-13720"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://gitlab.freedesktop.org/xorg/lib/libxfont",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"last_affected": "8cce9834b2e74dccad94ca0adf79ae5585e37d48"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:x.org:libxfont:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"last_affected": "1.5.2"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"libXfont-1.5.2",
"libXfont-1.5.1",
"libXfont-1.5.0",
"libXfont-1.4.99.901",
"libXfont-1.4.7",
"libXfont-1.4.6",
"libXfont-1.4.5",
"libXfont-1.4.4",
"libXfont-1.4.3",
"libXfont-1.4.2",
"libXfont-1.4.1",
"libXfont-1.4.0",
"libXfont-1.3.4",
"libXfont-1.3.3",
"libXfont-1.3.2",
"libXfont-1.3.1",
"libXfont-1.3.0",
"libXfont-1.2.9",
"libXfont-1.2.8",
"libXfont-1.2.7",
"libXfont-1.2.6",
"libXfont-1.2.5",
"libXfont-1.2.4",
"libXfont-1.2.3",
"libXfont-1.2.0",
"libxfont-1_1_0",
"XORG-7_1",
"XORG-7_0_99_901",
"XORG-7_0",
"XORG-6_99_99_904",
"MODULAR_COPY",
"XORG-6_99_99_903",
"XORG-6_8_99_903",
"XORG-6_99_99_902",
"XORG-6_8_99_902",
"XORG-6_99_99_901",
"XORG-6_99_99_900",
"XORG-6_8_99_901",
"XORG-6_8_99_900",
"XORG-6_8_99_16",
"XORG-6_8_99_15",
"XORG-6_8_99_14",
"XORG-6_8_99_13",
"XORG-6_8_99_12",
"sco_port_update-base",
"XORG-6_8_99_8",
"XORG-6_8_99_7",
"XORG-6_8_99_6",
"XORG-6_8_99_5",
"XORG-6_8_99_4",
"XORG-6_8_99_11",
"XORG-6_8_99_9",
"XORG-6_8_99_10",
"XORG-6_8_99_3",
"XORG-6_8_99_2",
"XORG-6_8_99_1",
"rel-0-6-1",
"lg3d-rel-0-7-0",
"lg3d-base",
"XORG-6_8_1_902",
"XORG-6_8_1_901",
"XORG-6_8_1",
"XORG-6_8_0",
"XORG-6_7_99_904",
"XORG-6_7_99_903",
"XORG-6_7_99_902",
"XORG-6_7_99_901",
"XORG-6_7_99_2",
"XORG-6_7_99_1",
"XACE-SELINUX-MERGE",
"xf86-4_4_99_1",
"xf86-4_4_0",
"xf86-4_3_99_903",
"xf86-4_3_99_903_special",
"xf86-012804-2330",
"xf86-4_3_99_902",
"xf86-4_3_99_901",
"xf86-4_3_99_16",
"xf86-4_3_0_1",
"PRE_xf86-4_3_0_1",
"XORG-MAIN"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2017-13720.json"
}
}
],
"modified": "2026-10-20T10:48:11.736774611Z",
"provider": "osv",
"references": [
"https://security.gentoo.org/glsa/201711-08",
"https://www.x.org/releases/individual/lib/libXfont2-2.0.2.tar.bz2",
"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"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:a:x.org:libxfont:2.0.0:*:*:*:*:*:*:*",
"cpe:2.3:a:x.org:libxfont:2.0.1:*:*:*:*:*:*:*"
],
"vendor_product": "x.org:libxfont",
"extracted_events": [
{
"range": [
{
"introduced": "2.0.0"
},
{
"last_affected": "2.0.0"
},
{
"introduced": "2.0.1"
},
{
"last_affected": "2.0.1"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2017-13720",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 380124,
"published_at": "2017-10-11T17:29:00.303+00:00"
}