CVE-2025-69648: GNU Binutils readelf DoS Vulnerability

CVE-2025-69648 Overview

GNU Binutils through version 2.45.1 contains a denial-of-service vulnerability in the readelf utility when processing specially crafted binaries with malformed DWARF .debug_rnglists data. A logic flaw in the DWARF parsing path causes readelf to repeatedly print the same warning message without making forward progress, resulting in a non-terminating output loop that requires manual interruption. This is classified as CWE-835 (Infinite Loop), and no evidence of memory corruption or code execution was observed.

Critical Impact

Attackers can craft malicious binaries that cause GNU Binutils readelf to enter an infinite loop, requiring manual process termination and potentially disrupting automated build pipelines, CI/CD systems, and binary analysis workflows.

Affected Products

• GNU Binutils through version 2.45.1
• Systems using readelf for binary analysis
• Automated build and CI/CD pipelines processing untrusted binaries

Discovery Timeline

• 2026-03-09 - CVE CVE-2025-69648 published to NVD
• 2026-03-11 - Last updated in NVD database

Technical Details for CVE-2025-69648

Vulnerability Analysis

This vulnerability exists within the DWARF debug information parsing functionality of GNU Binutils readelf. When processing a binary containing malformed .debug_rnglists data, a logic flaw prevents the parser from advancing through the data structure correctly. Instead of detecting the malformed input and gracefully handling the error, the parsing routine enters an infinite loop where it continuously emits the same warning message without progressing to the next data element.

The vulnerability requires local access to exploit, as an attacker must provide a crafted binary file for processing. While this does not result in memory corruption or arbitrary code execution, the infinite loop condition can exhaust system resources and disrupt automated binary analysis processes.

Root Cause

The root cause is CWE-835 (Infinite Loop) - a loop termination condition that fails to account for certain malformed input scenarios in the DWARF .debug_rnglists parsing logic. When the parser encounters specifically malformed debug data, the state variables that control loop iteration are not properly updated, causing the loop to repeat indefinitely.

Attack Vector

The attack vector requires local access where an attacker provides a crafted binary file to systems running GNU Binutils readelf. Potential attack scenarios include:

• Submitting malicious binaries to automated build systems or CI/CD pipelines
• Providing crafted ELF files to security analysis tools that invoke readelf
• Targeting development environments where binaries from untrusted sources are analyzed

The malformed .debug_rnglists section must be specifically crafted to trigger the infinite loop condition. When readelf attempts to parse the debug information, it becomes trapped in the non-terminating loop, continuously printing warning messages until manually interrupted or the process is killed.

Detection Methods for CVE-2025-69648

Indicators of Compromise

• Unusual CPU consumption by readelf processes lasting beyond expected execution time
• Excessive log file growth due to repeated warning messages from readelf
• Hung or unresponsive readelf processes in build pipelines or analysis workflows
• Process monitoring alerts for readelf instances exceeding normal execution thresholds

Detection Strategies

• Monitor for readelf processes with abnormally long execution times or high CPU usage
• Implement process timeouts for readelf invocations in automated pipelines
• Analyze system logs for repeated identical warning messages from Binutils tools
• Use file integrity monitoring to detect introduction of suspicious ELF binaries

Monitoring Recommendations

• Configure process resource limits (ulimit, cgroups) for readelf executions in production environments
• Implement alerting for readelf processes exceeding defined execution time thresholds
• Monitor build system logs for patterns indicating infinite loop conditions
• Track Binutils version deployments across infrastructure to identify vulnerable instances

How to Mitigate CVE-2025-69648

Immediate Actions Required

• Update GNU Binutils to a patched version that addresses the infinite loop condition
• Implement execution timeouts when running readelf on untrusted binary inputs
• Review and restrict sources of binary files processed by automated analysis systems
• Configure process resource limits to prevent runaway readelf processes from consuming excessive resources

Patch Information

A fix for this vulnerability has been committed to the GNU Binutils repository. The specific commit addressing this issue can be reviewed at the Sourceware Git Commit Log. Additional details are available in the Sourceware Bug Report #33641.

Organizations should update to the latest version of GNU Binutils that incorporates this fix. For systems where immediate updates are not feasible, implement the workarounds described below.

Workarounds

• Wrap readelf invocations with timeout utilities (e.g., timeout 60 readelf -a binary) to prevent infinite execution
• Implement input validation to reject binaries with suspicious or malformed DWARF sections before processing
• Use containerization or sandboxing for readelf operations on untrusted binaries to limit resource consumption
• Consider using alternative tools for binary analysis on untrusted inputs until patching is complete

# Configuration example - Using timeout wrapper for readelf
# Limits readelf execution to 60 seconds maximum
timeout --signal=SIGKILL 60 readelf -a /path/to/binary

# Using ulimit to restrict CPU time for readelf processes
ulimit -t 120 && readelf -a /path/to/binary

# Systemd service example with resource limits
# [Service]
# ExecStart=/usr/bin/readelf -a /path/to/binary
# TimeoutStartSec=60
# CPUQuota=50%
# MemoryMax=512M