A stack overflow vulnerability exists in the libexpat library due to the way it handles recursive entity expansion in XML documents. When parsing an XML document with deeply nested entity references, libexpat can be forced to recurse indefinitely, exhausting the stack space and causing a crash. This issue could lead to denial of service (DoS) or, in some cases, exploitable memory corruption, depending on the environment and library usage.
The severity of this vulnerability is classified as high, with a CVSS score of 7.5. The potential for exploitation makes this a significant concern for organizations utilizing the libexpat library.
Risk to organizations includes system crashes and potential data corruption, which can disrupt services and impact business operations. Organizations should prioritize patching immediately.
As the vulnerability is confirmed to have an exploit available, it is crucial for defenders to take swift action to mitigate risks associated with this vulnerability.
Vulnerability Details
This vulnerability allows a stack overflow to occur in the libexpat library, specifically when it processes XML documents with deeply nested entity references. The vulnerability is classified under CWE-674.
The CVSS score for this vulnerability is 7.5, indicating high severity. The attack vector is network-based, with low attack complexity, no privileges required, and no user interaction needed.
Technical Analysis
The root cause of this vulnerability lies in improper handling of recursive entity expansion within the libexpat library. When an XML document contains deeply nested entities, the library can enter into an infinite recursion, resulting in stack exhaustion.
The attack vector is network-based, as an attacker can send a specially crafted XML document to a service utilizing libexpat. The attack complexity is low, and there are no privileges required or user interaction needed for the attack to succeed.
The impact on availability is high, as the exploitation of this vulnerability can lead to service outages. However, confidentiality and integrity impacts are minimal, as no data is compromised in the process.
Risk & Impact Analysis
Organizations utilizing the libexpat library are at risk of service disruption due to possible crashes resulting from this vulnerability. The blast radius is significant, as any application relying on libexpat could be affected.
Given the CVSS score of 7.5 and the confirmed availability of an exploit, organizations should address this vulnerability in their priority patch cycle to avoid potential Denial of Service attacks.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | Yes |
Public PoC | Yes |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
All versions prior to vendor patch are affected by this vulnerability.
Mitigation & Remediation
Organizations should apply the latest patches for the libexpat library to mitigate this vulnerability. If a patch is unavailable, consider implementing input validation and limiting the depth of entity references in XML documents to prevent exploitation.
For more information on penetration testing and to validate the effectiveness of remediation, organizations can refer to penetration testing services.
Detection Guidance
Monitoring for unusual crashes in applications utilizing the libexpat library is essential. Log indicators from application servers and analyze behavior anomalies to identify potential exploitation.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability may reflect broader challenges in XML parsing libraries. Organizations must ensure that their libraries are kept up-to-date and assess their overall security posture.
Security teams should take note of the trends in vulnerabilities related to XML processing and adapt their defensive strategies accordingly.
For additional insights on vulnerability management, organizations can explore the vulnerability management program design.
Additionally, organizations should review their approach to penetration testing methodology to enhance their security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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