Stack Overflow Vulnerability in Expat Library Affecting XML Parsing

CVE-2024-8176

What is CVE-2024-8176?

CVE-2024-8176 is a notable vulnerability found in the libexpat library, which is primarily used for XML parsing. This library is integral to various applications that rely on XML for data exchange and document formatting. The vulnerability arises from how libexpat processes recursive entity expansion in XML documents. If exploited, an attacker could leverage deeply nested entity references to cause a stack overflow, resulting in potential crashes and undermining system stability. Organizations using affected software may face severe operational disruptions and exposure to broader security risks.

Technical Details

The vulnerability is characterized as a stack overflow caused by improper handling of recursive entity expansion within XML documents. During the parsing of an XML file with intricate nested references, libexpat can enter an infinite recursion state. This behavior leads to a stack exhaustion, ultimately resulting in a crash of the application that utilizes the library. Depending on the specific environmental factors and use case, this could transition into memory corruption, elevating the risk associated with the flaw.

Potential Impact of CVE-2024-8176

1. Denial of Service (DoS): The primary impact is the ability to trigger application crashes, leading to a denial of service scenario. For systems relying heavily on XML processing, this could mean significant downtime and disruption of services.

2. Memory Corruption: In specific environments, exploiting this vulnerability can result in memory corruption. This may adversely affect the integrity of data being processed and can lead to unpredictable program behavior or data loss.

3. Operational Risks: Organizations leveraging applications built on the libexpat library may discover that their software becomes vulnerable to secondary attacks or exploitation attempts, particularly if it doesn't robustly manage XML inputs. This threat amplifies the need for effective security practices around XML data handling.

References