CVE-2025-69651: GNU Binutils readelf DoS Vulnerability

CVE-2025-69651 Overview

GNU Binutils through version 2.46 contains a memory safety vulnerability in the readelf utility that can lead to an invalid pointer free when processing a specially crafted ELF binary. The vulnerability occurs when malformed relocation or symbol data causes dump_relocations to return early due to parsing errors, leaving the internal all_relocations array partially uninitialized. Subsequently, process_got_section_contents() may attempt to free an invalid r_symbol pointer, triggering memory corruption detection in glibc and causing the program to terminate with SIGABRT.

Critical Impact

This vulnerability allows attackers to cause denial of service by crashing the readelf utility when analyzing malicious ELF files. While no evidence of further memory corruption or code execution was observed, the impact can disrupt development workflows and automated analysis pipelines that rely on binutils for ELF processing.

Affected Products

• GNU Binutils through version 2.46
• All platforms running vulnerable versions of readelf
• Development environments and CI/CD pipelines utilizing binutils for binary analysis

Discovery Timeline

• 2026-03-06 - CVE-2025-69651 published to NVD
• 2026-03-10 - Last updated in NVD database

Technical Details for CVE-2025-69651

Vulnerability Analysis

This vulnerability represents a classic memory safety issue stemming from improper error handling in the readelf component of GNU Binutils. The root cause lies in the interaction between two functions: dump_relocations() and process_got_section_contents(). When dump_relocations() encounters parsing errors while processing malformed ELF relocation or symbol data, it returns early without properly initializing all elements of the all_relocations array.

The vulnerability is triggered locally when a user analyzes a crafted ELF binary, requiring user interaction to open or process the malicious file. While the attack complexity is low once the malicious file is in place, the impact is limited to availability—causing the readelf process to crash without affecting confidentiality or integrity.

Root Cause

The vulnerability stems from insufficient initialization and validation of the all_relocations array when error conditions occur during ELF parsing. When dump_relocations() exits early due to malformed input, pointers within the array may contain uninitialized or garbage values. The process_got_section_contents() function subsequently treats these invalid pointers as valid memory addresses and attempts to free them, triggering glibc's memory corruption detection mechanisms.

This is classified as CWE-476 (NULL Pointer Dereference) and represents a failure to properly handle error states during memory management operations.

Attack Vector

The attack requires local access to the target system and user interaction—specifically, the victim must process a malicious ELF binary using the vulnerable readelf utility. An attacker could distribute crafted ELF files through various channels such as software repositories, email attachments, or compromised development dependencies.

When the victim runs readelf against the malicious file, the parsing error in the relocation data triggers the invalid free condition. The glibc memory allocator detects the corruption attempt and terminates the process with SIGABRT. While this limits the impact to denial of service, it can be particularly disruptive in automated environments that rely on binutils for binary analysis, such as CI/CD pipelines, malware analysis sandboxes, or development toolchains.

The vulnerability mechanism involves malformed relocation or symbol entries in the ELF file structure that cause early return from dump_relocations(), followed by improper cleanup in process_got_section_contents(). For technical details on the specific code paths involved, see the Sourceware Bug Report #33700.

Detection Methods for CVE-2025-69651

Indicators of Compromise

• Unexpected readelf process terminations with SIGABRT signal
• Core dumps or crash reports from binutils components during ELF analysis
• Unusual or malformed ELF files appearing in development directories or package repositories
• Repeated crashes when processing specific ELF binaries from untrusted sources

Detection Strategies

• Monitor for SIGABRT signals from readelf processes, which indicate memory corruption detection
• Implement file integrity monitoring on ELF binaries in development and analysis environments
• Use static analysis tools to validate ELF file structure before processing with vulnerable binutils versions
• Deploy sandboxed environments for analyzing untrusted ELF binaries to contain potential crashes

Monitoring Recommendations

• Configure crash reporting to capture and alert on readelf SIGABRT events
• Implement logging for all ELF file analysis operations to identify potentially malicious files
• Monitor CI/CD pipeline health for unusual binutils failures that may indicate exploitation attempts
• Review system logs for patterns of repeated binutils crashes against specific files

How to Mitigate CVE-2025-69651

Immediate Actions Required

• Update GNU Binutils to the latest patched version that addresses this vulnerability
• Avoid processing ELF binaries from untrusted sources until the patch is applied
• Implement sandboxing for ELF analysis workflows to contain potential crashes
• Review recent ELF files processed that may have caused unexplained crashes

Patch Information

GNU has released a fix for this vulnerability. The patch is available through the official Sourceware Git repository at commit ea4bc025abdba85a90e26e13f551c16a44bfa921. System administrators should update to a binutils version that includes this commit or apply the patch manually if a distribution update is not yet available.

For detailed patch information, see the Sourceware Git Commit Details.

Workarounds

• Run readelf in a sandboxed environment or container when analyzing untrusted ELF files
• Implement pre-validation of ELF files using alternative tools before processing with binutils
• Configure resource limits and monitoring for binutils processes to detect and contain crashes
• Use alternative ELF analysis tools for untrusted binaries until the patch is applied

# Configuration example
# Run readelf in a resource-limited sandbox using firejail
firejail --quiet --noprofile --noroot readelf -a suspicious.elf

# Or use a container for isolation
docker run --rm -v $(pwd):/work:ro binutils-sandbox readelf -a /work/suspicious.elf