Skip to main content

Libxslt CVE-2019-18197

HIGH
Use After Free (CWE-416)
2019-10-18 cve@mitre.org
7.5
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

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

Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, high complexity, no privileges required, user interaction required. EPSS exploitation probability: 4.53%.

Exploit ScenarioDerived

A remote attacker could access freed memory to execute arbitrary code or crash the application by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 4.5% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required. This Use After Free vulnerability could allow attackers to access freed memory to execute arbitrary code or crash the application.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Use smart pointers or garbage-collected languages. Set pointers to NULL after freeing. Enable memory sanitizers.

Affected Packages

rubygems nokogiri fix: 1.10.5

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in rubygems

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 Use After Free (CWE-416), which allows attackers to access freed memory to execute arbitrary code or crash the application. In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed. Affected products include: Xmlsoft Libxslt, Canonical Ubuntu Linux, Debian Debian Linux.

Know when Libxslt gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 7.5 HIGH
AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

DescriptionCVE.org

In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclosed.

Threat Intelligence Overview

EPSS Score
4.5%
Top 11% exploitable
Data Quality
4 sources
Confidence: Medium

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 4.5%
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
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

43
Low Medium High Critical
KEV: 0
EPSS: +5
CVSS: +38
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

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

Affected Products (CPE)CVE.org

cpe:2.3:a:xmlsoft:libxslt:1.1.33:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
CVE-2024-55549 HIGH POC
7.8 Mar 14

xsltGetInheritedNsList in libxslt before 1.1.43 has a use-after-free issue related to exclusion of result prefixes. Rate

CVE-2025-24855 HIGH POC
7.8 Mar 14

numbers.c in libxslt before 1.1.43 has a use-after-free because, in nested XPath evaluations, an XPath context node can

CVE-2022-29824 MEDIUM POC
6.5 May 03

In libxml2 before 2.9.14, several buffer handling functions in buf.c (xmlBuf*) and tree.c (xmlBuffer*) don't check for i

CVE-2016-4607 CRITICAL
9.8 Jul 22

libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows,

CVE-2012-6139 MEDIUM POC
5.0 Apr 12

libxslt before 1.1.28 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an (

CVE-2016-4610 CRITICAL
9.8 Jul 22

libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows,

CVE-2016-4609 CRITICAL
9.8 Jul 22

libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows,

CVE-2016-4608 CRITICAL
9.8 Jul 22

libxslt in Apple iOS before 9.3.3, OS X before 10.11.6, iTunes before 12.4.2 on Windows, iCloud before 5.2.1 on Windows,

CVE-2019-11068 CRITICAL
9.8 Apr 10

libxslt through 1.1.33 allows bypass of a protection mechanism because callers of xsltCheckRead and xsltCheckWrite permi

CVE-2015-7995 MEDIUM POC
5.0 Nov 17

The xsltStylePreCompute function in preproc.c in libxslt 1.1.28 does not check if the parent node is an element, which a

CVE-2017-5029 HIGH
8.8 Apr 24

The xsltAddTextString function in transform.c in libxslt 1.1.29, as used in Blink in Google Chrome prior to 57.0.2987.98

CVE-2021-30560 HIGH
8.8 Aug 03

Use after free in Blink XSLT in Google Chrome prior to 91.0.4472.164 allowed a remote attacker to potentially exploit he

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy