CVE-2025-5244: GNU Binutils Buffer Overflow Vulnerability

CVE-2025-5244 Overview

A critical memory corruption vulnerability has been identified in GNU Binutils versions up to 2.44. The vulnerability exists in the elf_gc_sweep function within the bfd/elflink.c file of the linker (ld) component. Successful exploitation of this vulnerability could allow an attacker with local access to cause memory corruption, potentially leading to code execution or denial of service conditions.

Critical Impact

Local attackers can exploit the memory corruption vulnerability in the ELF garbage collection sweep function, potentially compromising system integrity through malicious object file processing.

Affected Products

• GNU Binutils versions up to and including 2.44
• Systems using the ld linker component
• Build environments and development toolchains utilizing vulnerable Binutils versions

Discovery Timeline

• May 27, 2025 - CVE-2025-5244 published to NVD
• October 3, 2025 - Last updated in NVD database

Technical Details for CVE-2025-5244

Vulnerability Analysis

This vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). The flaw resides in the elf_gc_sweep function, which is responsible for garbage collection during the ELF linking process. During the sweep phase, improper handling of memory operations can lead to corruption of memory structures.

The vulnerability requires local access to exploit, meaning an attacker would need to have the ability to execute the linker with specially crafted input files. While the exploit has been publicly disclosed, the local attack vector and authentication requirements limit the exposure surface compared to network-exploitable vulnerabilities.

Root Cause

The root cause stems from improper memory bounds checking within the elf_gc_sweep function in bfd/elflink.c. During the ELF garbage collection sweep process, certain memory operations do not properly validate buffer boundaries, leading to potential memory corruption when processing malformed or specially crafted ELF object files.

Attack Vector

The attack vector requires local access to the target system. An attacker would need to craft a malicious ELF object file and have the vulnerable linker process it. This could occur in scenarios such as:

The vulnerability manifests during the linking phase when the ld linker processes ELF files with specific characteristics that trigger the memory corruption in the garbage collection sweep routine. An attacker could provide malicious input through build systems that process untrusted source code or object files. Technical details are available in the Sourceware Bugzilla Report.

Detection Methods for CVE-2025-5244

Indicators of Compromise

• Unexpected crashes or segmentation faults in the ld linker during build processes
• Unusual memory access patterns or error messages related to elf_gc_sweep function
• Presence of suspicious or malformed ELF object files in build directories

Detection Strategies

• Monitor build system logs for linker crashes with stack traces referencing elf_gc_sweep or elflink.c
• Implement file integrity monitoring on build toolchains to detect unauthorized Binutils modifications
• Use memory sanitizers (ASan, MSan) during development builds to detect memory corruption early

Monitoring Recommendations

• Enable verbose logging for build systems to capture linker invocations and errors
• Implement automated version checking for GNU Binutils installations across development environments
• Set up alerts for abnormal linker behavior patterns in CI/CD pipelines

How to Mitigate CVE-2025-5244

Immediate Actions Required

• Upgrade GNU Binutils to version 2.45 or later immediately
• Audit build environments and development systems for vulnerable Binutils versions
• Restrict access to build systems to authorized personnel only
• Validate the integrity of object files processed by the linker from untrusted sources

Patch Information

GNU has released a fix for this vulnerability in Binutils version 2.45. The patch addressing this issue is available in the Sourceware Git Commit Log. The commit hash for the fix is d1458933830456e54223d9fc61f0d9b3a19256f5. Organizations should prioritize upgrading to version 2.45 or applying the specific patch to address this vulnerability.

Workarounds

• Limit linker usage to trusted object files only until patching is complete
• Implement network segmentation for build servers to reduce exposure
• Use containerized build environments with restricted capabilities
• Consider using alternative toolchains temporarily if upgrading is not immediately feasible

# Verify current Binutils version
ld --version

# Check for vulnerable version (versions <= 2.44 are affected)
# If version is 2.44 or earlier, upgrade is required

# Update Binutils on Debian/Ubuntu systems
sudo apt-get update && sudo apt-get install binutils

# Update Binutils on RHEL/CentOS systems
sudo yum update binutils

# Verify upgrade was successful
ld --version