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Libxfont CVE-2017-13720

HIGH
Out-of-bounds Read (CWE-125)
2017-10-11 cve@mitre.org
7.1
CVSS 3.0 · NVD
View

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, read limits
MITRE ATT&CK

1 technique across 1 tactic: Collection

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.1 (HIGH). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required. EPSS exploitation probability: 0.06%.

Exploit ScenarioDerived

A local attacker with access to the system could read data from memory outside the intended buffer boundaries.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.1% exploitation probability (EPSS)

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AnalysisAI

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. Rated high severity (CVSS 7.1), this vulnerability is low attack complexity. This Out-of-bounds Read vulnerability could allow attackers to read data from memory outside the intended buffer boundaries.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Validate array indices and buffer lengths. Use memory-safe languages. Enable AddressSanitizer during testing.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Out-of-bounds Read (CWE-125), which allows attackers to read data from memory outside the intended buffer boundaries. 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 include: X.Org Libxfont. Version information: through 1.5.2.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.1 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

DescriptionCVE.org

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.

Threat Intelligence Overview

EPSS Score
0.1%
Top 80% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.1%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Defer
Exploitation· derived
None
System Exposure· derived
Small
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

36
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +36
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:x.org:libxfont:*:*:*:*:*:*:*:*
cpe:2.3:a:x.org:libxfont:2.0.0:*:*:*:*:*:*:*
cpe:2.3:a:x.org:libxfont:2.0.1:*:*:*:*:*:*:*
CVE-2013-6462 CRITICAL POC
9.3 Jan 09

Stack-based buffer overflow in the bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont 1.1 through 1.4.6 al

CVE-2015-1804 HIGH
8.5 Mar 20

The bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not proper

CVE-2026-56003 HIGH
8.8 Jul 08

Arbitrary code execution in libXfont2 before 2.0.8 lets an authenticated X client corrupt heap memory inside the X serve

CVE-2026-56002 HIGH
8.8 Jul 08

Heap-based code execution in libXfont2 before 2.0.8 allows an authenticated X client to run arbitrary code inside the X

CVE-2026-56001 HIGH
8.8 Jul 08

Arbitrary code execution in the X.Org libXfont2 library (versions before 2.0.8) stems from a heap buffer overflow in the

CVE-2015-1802 HIGH
8.5 Mar 20

The bdfReadProperties function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 allows remote a

CVE-2015-1803 HIGH
8.5 Mar 20

The bdfReadCharacters function in bitmap/bdfread.c in X.Org libXfont before 1.4.9 and 1.5.x before 1.5.1 does not proper

CVE-2014-0211 HIGH
7.5 May 15

Multiple integer overflows in the (1) fs_get_reply, (2) fs_alloc_glyphs, and (3) fs_read_extent_info functions in X.Org

CVE-2014-0210 HIGH
7.5 May 15

Multiple buffer overflows in X.Org libXfont before 1.4.8 and 1.4.9x before 1.4.99.901 allow remote font servers to execu

CVE-2017-13722 HIGH
7.1 Oct 11

In the pcfGetProperties function in bitmap/pcfread.c in libXfont through 1.5.2 and 2.x before 2.0.2, a missing boundary

CVE-2017-16611 MEDIUM
5.5 Dec 01

In libXfont before 1.5.4 and libXfont2 before 2.0.3, a local attacker can open (but not read) files on the system as roo

CVE-2014-0209 MEDIUM
4.6 May 15

Multiple integer overflows in the (1) FontFileAddEntry and (2) lexAlias functions in X.Org libXfont before 1.4.8 and 1.4

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