CVE-2025-0395: GNU C Library Buffer Overflow Vulnerability

CVE-2025-0395 Overview

When the assert() function in the GNU C Library versions 2.13 to 2.40 fails, it does not allocate enough space for the assertion failure message string and size information, which may lead to a buffer overflow if the message string size aligns to page size.

Critical Impact

This vulnerability can cause a denial of service (DoS) by triggering a buffer overflow in the library.

Affected Products

• GNU C Library 2.13
• GNU C Library 2.40
• Not Available

Discovery Timeline

• 2025-01-22T13:15:20.933 - CVE CVE-2025-0395 published to NVD
• 2025-04-30T05:15:46.707 - Last updated in NVD database

Technical Details for CVE-2025-0395

Vulnerability Analysis

The vulnerability resides in the assert() function of the GNU C Library where insufficient space is allocated for the failure message, potentially leading to buffer overflow vulnerabilities. This could cause the application or system to crash, resulting in a denial of service.

Root Cause

Insufficient buffer size allocation during the failure of the assert() function when the message size aligns with the page size.

Attack Vector

Network-based attacks can exploit this vulnerability, potentially causing denial of service conditions across affected systems.

// Example exploitation code (sanitized)
void exploit_assert() {
  char buffer[64];
  // Potentially large message triggering buffer overflow
  strcpy(buffer, "very large assertion failure message causing overflow");
}

Detection Methods for CVE-2025-0395

Indicators of Compromise

• Unexpected program crashes
• Log entries indicating failed assertions
• System performance degradation

Detection Strategies

Network monitoring tools can be configured to detect unusual traffic that might indicate exploitation attempts. Intrusion detection systems (IDS) should be updated with signatures to recognize attempts to exploit this vulnerability.

Monitoring Recommendations

Regularly monitor application logs for assertion failures. Implement anomaly detection to identify deviations in network and application performance metrics.

How to Mitigate CVE-2025-0395

Immediate Actions Required

• Update GNU C Library to a patched version immediately
• Implement network-based security controls to block exploitation
• Conduct regular security audits and vulnerability assessments

Patch Information

Vendors have released patches to mitigate this vulnerability. It is strongly advised to apply these patches as soon as they become available for your systems.

Workarounds

Limit exposure by ensuring that sensitive systems are not directly accessible from uncontrolled networks. Regularly audit and harden your applications and environments.

# Configuration example
sudo apt-get update
sudo apt-get install --only-upgrade glibc