CVE-2025-69652: GNU Binutils readelf DoS Vulnerability

CVE-2025-69652 Overview

GNU Binutils through version 2.46 contains a vulnerability in the readelf utility that leads to an application abort (SIGABRT) when processing a crafted ELF binary with malformed DWARF abbrev or debug information. The vulnerability stems from incomplete state cleanup in the process_debug_info() function, which allows an invalid debug_info_p state to propagate into DWARF attribute parsing routines. When certain malformed attributes result in an unexpected data length of zero, the byte_get_little_endian() function triggers a fatal abort, causing a denial of service condition.

Critical Impact

An attacker can cause readelf to abort when processing a specially crafted ELF binary, resulting in denial of service. While no memory corruption or code execution has been observed, this can disrupt development workflows and automated build systems that rely on binutils for binary analysis.

Affected Products

• GNU Binutils through version 2.46
• All platforms running vulnerable versions of binutils
• Development and build systems utilizing readelf for ELF binary analysis

Discovery Timeline

• 2026-03-06 - CVE CVE-2025-69652 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2025-69652

Vulnerability Analysis

This vulnerability represents an Improper Cleanup on Thrown Exception issue (CWE-460) in the GNU Binutils readelf component. The flaw occurs during the parsing of DWARF debugging information contained within ELF binaries. When readelf processes debug sections, the process_debug_info() function is responsible for iterating through compilation units and their associated debug information entries.

The vulnerability manifests when the function encounters malformed DWARF abbreviation tables or corrupted debug information. Under these conditions, the function fails to properly clean up or reset the debug_info_p state variable before proceeding to parse subsequent DWARF attributes. This invalid state then propagates through the attribute parsing chain.

When the malformed attributes result in a computed data length of zero being passed to byte_get_little_endian(), the function's internal validation triggers an assertion failure or explicit abort, terminating the readelf process immediately.

Root Cause

The root cause is incomplete state cleanup in process_debug_info() when handling error conditions or malformed input. The CWE-460 classification indicates that when an exception or error condition occurs during DWARF parsing, the cleanup code fails to restore all state variables to safe values. This allows corrupted or invalid state (specifically the debug_info_p pointer and associated length values) to persist and affect subsequent parsing operations, ultimately leading to the abort condition in byte_get_little_endian().

Attack Vector

This vulnerability requires local access, where an attacker must convince a user or automated system to process a maliciously crafted ELF binary using readelf. Attack scenarios include:

1. Supply Chain Attacks: Submitting malformed ELF binaries to automated build or analysis pipelines that use readelf for binary inspection
2. Development Environment Disruption: Providing crafted object files or libraries to developers who routinely analyze binaries
3. CI/CD Pipeline Disruption: Introducing malformed binaries into continuous integration systems that perform binary analysis as part of their workflow

The attack does not require any special privileges and can be triggered without user interaction beyond executing readelf against the crafted file. No evidence of memory corruption or code execution capability has been observed; the impact is strictly limited to denial of service through process termination.

Detection Methods for CVE-2025-69652

Indicators of Compromise

• Unexpected readelf process terminations with SIGABRT signals
• Core dump files generated by readelf crashes in analysis directories
• Build or CI/CD pipeline failures related to binary analysis stages
• System logs showing repeated readelf abort events

Detection Strategies

• Monitor for SIGABRT signals from readelf processes using system auditing tools
• Implement crash reporting for binutils utilities in development environments
• Review build system logs for unexpected readelf failures during binary processing
• Use file integrity monitoring to detect introduction of potentially malicious ELF files

Monitoring Recommendations

• Enable core dump collection for binutils processes to facilitate forensic analysis
• Configure build systems to alert on repeated readelf failures
• Implement sandboxing for binary analysis operations to contain potential denial of service impacts
• Monitor file submission sources in automated analysis pipelines for suspicious patterns

How to Mitigate CVE-2025-69652

Immediate Actions Required

• Upgrade GNU Binutils to a patched version that includes the fix (commit 44b79abd0fa12e7947252eb4c6e5d16ed6033e01)
• Review and validate ELF binaries from untrusted sources before processing with vulnerable versions
• Implement process isolation for readelf operations on untrusted files
• Consider using alternative analysis tools until patching is complete

Patch Information

A fix has been committed to the binutils-gdb repository. The patch is available at the Sourceware Git repository with commit hash 44b79abd0fa12e7947252eb4c6e5d16ed6033e01. Users should update to a binutils version that includes this commit. Additional details about the vulnerability and fix can be found in Sourceware Bug Report #33701.

Workarounds

• Run readelf operations in isolated containers or sandboxed environments to limit denial of service impact
• Implement input validation to reject ELF files with obviously malformed DWARF sections before processing
• Use timeout mechanisms when running readelf on untrusted input to prevent workflow disruption
• Temporarily disable automated binary analysis on untrusted input sources until patching is complete

# Example: Run readelf in a sandboxed environment with timeout
timeout 30 firejail --quiet --private readelf -w suspicious_binary.elf

# Example: Wrapper script to catch readelf failures
#!/bin/bash
if ! readelf -w "$1" 2>/dev/null; then
    echo "Warning: readelf failed for $1 - possible malformed binary"
    exit 1
fi