CVE-2025-69646: Binutils objdump DoS Vulnerability

CVE-2025-69646 Overview

Binutils objdump contains a denial-of-service vulnerability when processing a crafted binary with malformed DWARF debug_rnglists data. A logic error in the handling of the debug_rnglists header can cause objdump to repeatedly print the same warning message and fail to terminate, resulting in an unbounded logging loop until the process is interrupted. The issue was observed in binutils 2.44. A local attacker can exploit this vulnerability by supplying a malicious input file, leading to excessive CPU and I/O usage and preventing completion of the objdump analysis.

Critical Impact

Local attackers can cause complete denial of service by supplying crafted binaries with malformed DWARF debug_rnglists data, leading to resource exhaustion through unbounded logging loops.

Affected Products

• GNU Binutils 2.44
• Systems using objdump for binary analysis
• Development and debugging environments relying on Binutils

Discovery Timeline

• 2026-03-06 - CVE CVE-2025-69646 published to NVD
• 2026-03-10 - Last updated in NVD database

Technical Details for CVE-2025-69646

Vulnerability Analysis

This vulnerability is classified as a Resource Exhaustion issue (CWE-400) affecting the objdump utility within GNU Binutils. The flaw stems from improper handling of malformed DWARF debugging information, specifically within the debug_rnglists section of binary files.

When objdump processes a crafted binary containing malformed DWARF debug_rnglists data, a logic error in header validation causes the tool to enter an infinite loop. During this loop, objdump repeatedly prints the same warning message without advancing through the data or terminating. This behavior results in unbounded CPU consumption, excessive I/O operations from continuous logging, and prevents the analysis task from completing.

The vulnerability requires local access to exploit, as an attacker must provide a malicious binary file as input to objdump. While this limits the attack surface compared to remotely exploitable vulnerabilities, it poses significant risk in automated build systems, CI/CD pipelines, and environments where untrusted binaries may be analyzed.

Root Cause

The root cause is a logic error in the debug_rnglists header parsing code within objdump. When encountering malformed header data, the parser fails to properly advance its position or terminate gracefully. Instead of reporting an error and moving on or exiting, the code continues to re-process the same malformed data indefinitely. This lack of proper boundary checking and loop termination conditions allows the infinite loop condition to occur.

Attack Vector

The attack vector is local, requiring an attacker to supply a specially crafted binary file to objdump. Attack scenarios include:

• Submitting malicious binaries to automated analysis systems that use objdump
• Placing crafted executables in repositories that trigger CI/CD pipelines using objdump for inspection
• Social engineering developers to analyze a malicious binary
• Targeting reverse engineering environments where unknown binaries are routinely examined

The exploitation does not require any special privileges beyond the ability to provide input to objdump. Once triggered, the unbounded loop will consume CPU resources and generate excessive log output until the process is manually terminated or the system runs out of resources.

Detection Methods for CVE-2025-69646

Indicators of Compromise

• Objdump processes consuming 100% CPU for extended periods without completing
• Excessive disk I/O or log file growth from repeated warning messages
• Hung or unresponsive build pipelines involving binary analysis
• Process monitoring showing objdump instances that never terminate

Detection Strategies

• Monitor for objdump processes exceeding expected execution timeframes
• Implement resource limits (ulimit, cgroups) on objdump and related binary analysis tools
• Configure process watchdogs to detect and terminate runaway analysis processes
• Review system logs for patterns of repeated identical warning messages from objdump

Monitoring Recommendations

• Deploy CPU usage alerts for binary analysis tooling in automated environments
• Implement timeout mechanisms for all objdump invocations in CI/CD pipelines
• Monitor log directories for rapid growth patterns that may indicate infinite loop conditions
• Use process accounting to track objdump execution times and flag anomalies

How to Mitigate CVE-2025-69646

Immediate Actions Required

• Update GNU Binutils to a patched version containing the fix (commit 598704a00cbac5e85c2bedd363357b5bf6fcee33)
• Implement execution timeouts for objdump in automated systems
• Validate binary sources before analysis to reduce exposure to malicious files
• Configure resource limits for processes performing binary analysis

Patch Information

The vulnerability has been addressed in the GNU Binutils source repository. The fix is available in Sourceware Git Commit 598704a. Users should update to a version of Binutils that includes this commit. Additional details about the issue can be found in Sourceware Bug Report #33638.

Workarounds

• Run objdump with timeout commands to prevent indefinite execution
• Use containerization to isolate objdump processes and limit resource consumption
• Implement file validation checks before passing binaries to objdump
• Consider alternative binary analysis tools until the patch can be applied

# Configuration example
# Run objdump with a 60-second timeout to prevent infinite loops
timeout 60 objdump -d suspicious_binary.elf

# Use cgroups to limit CPU and memory for objdump processes
cgexec -g cpu,memory:binutils_analysis objdump -d binary_file

# Set ulimit for CPU time before running objdump
ulimit -t 120 && objdump -d untrusted_binary