CVE-2022-25314 – CVE-2022-25314 is an integer overflow vulnerabi... (How to Fix)

Q: What is the severity of CVE-2022-25314?

CVE-2022-25314 has a CVSS score of 7.5 (HIGH). CVE-2022-25314 is an integer overflow vulnerability in Expat's copyString function that can lead to heap buffer overflow. This allows attackers to potentially execute arbitrary code or cause denial of service. Any system using vulnerable versions of libexpat (Expat XML parser library) is affected.

📋 TL;DR

CVE-2022-25314 is an integer overflow vulnerability in Expat's copyString function that can lead to heap buffer overflow. This allows attackers to potentially execute arbitrary code or cause denial of service. Any system using vulnerable versions of libexpat (Expat XML parser library) is affected.

💻 Affected Systems

Products:

Expat (libexpat)
Any software using vulnerable libexpat versions

Versions: All versions before 2.4.5

Operating Systems: Linux, Windows, macOS, BSD, Embedded systems

Default Config Vulnerable: ⚠️ Yes

Notes: Affects all configurations using vulnerable libexpat versions. Many Linux distributions and embedded devices include libexpat.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise, data theft, or ransomware deployment.

🟠

Likely Case

Denial of service through application crashes, potentially leading to service disruption.

🟢

If Mitigated

Limited impact with proper memory protections (ASLR, DEP) and sandboxing, likely resulting in crashes only.

🌐 Internet-Facing: MEDIUM - Many internet-facing applications use XML parsing, but exploitation requires specific conditions.

🏢 Internal Only: LOW - Internal systems typically have more controlled XML input sources.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires attacker-controlled XML input. Proof-of-concept code is available in security advisories.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.4.5 and later

Vendor Advisory: https://github.com/libexpat/libexpat/pull/560

Restart Required: Yes

Instructions:

1. Update libexpat to version 2.4.5 or later. 2. For Linux: Use package manager (apt-get update && apt-get upgrade libexpat1). 3. For Windows: Download from official source. 4. Recompile applications if statically linked. 5. Restart affected services.

🔧 Temporary Workarounds

Input Validation

all

Implement strict XML input validation and size limits

Memory Protection

linux

Enable ASLR and DEP to reduce exploit effectiveness

sysctl -w kernel.randomize_va_space=2

🧯 If You Can't Patch

Implement network segmentation to isolate vulnerable systems
Deploy web application firewall with XML parsing protection rules

🔍 How to Verify

Check if Vulnerable:

Check libexpat version: expat --version or check package version (dpkg -l | grep libexpat).

Check Version:

expat --version 2>/dev/null || dpkg -l libexpat1 2>/dev/null || rpm -q expat 2>/dev/null

Verify Fix Applied:

Confirm version is 2.4.5 or later and test XML parsing functionality.

📡 Detection & Monitoring

Log Indicators:

Application crashes with segmentation faults
Unusual XML parsing errors
Memory allocation failures

Network Indicators:

Large or malformed XML payloads to services
XML parsing services receiving unexpected traffic

SIEM Query:

source="application.log" AND ("segmentation fault" OR "libexpat" OR "XML parse error")

📊 Metadata

CVE ID: CVE-2022-25314

CVSS v3 Score: 7.5 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-190

Published: February 18, 2022

Last Updated: May 5, 2025

🔗 References

http://www.openwall.com/lists/oss-security/2022/02/19/1 Mailing List,Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf Third Party Advisory
https://github.com/libexpat/libexpat/pull/560 Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFRBA3UQVIQKXTBUQXDWQOVWNBKLERU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y27XO3JMKAOMQZVPS3B4MJGEAHCZF5OM/
https://security.gentoo.org/glsa/202209-24 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220303-0008/ Third Party Advisory
https://www.debian.org/security/2022/dsa-5085 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch,Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/02/19/1 Mailing List,Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-484086.pdf Third Party Advisory
https://github.com/libexpat/libexpat/pull/560 Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3UFRBA3UQVIQKXTBUQXDWQOVWNBKLERU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y27XO3JMKAOMQZVPS3B4MJGEAHCZF5OM/
https://security.gentoo.org/glsa/202209-24 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220303-0008/ Third Party Advisory
https://www.debian.org/security/2022/dsa-5085 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch,Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2022-25314, you might also want to check these: