CVE-2025-0840: GNU Binutils Buffer Overflow Vulnerability

CVE-2025-0840 Overview

A stack-based buffer overflow vulnerability has been identified in GNU Binutils up to version 2.43. This vulnerability exists within the disassemble_bytes function located in binutils/objdump.c. Through manipulation of the buf argument, an attacker can trigger a buffer overflow condition. While the attack can be initiated remotely, exploitation is considered difficult due to the high complexity of the attack.

Critical Impact
Successful exploitation of this stack-based buffer overflow could allow attackers to cause denial of service conditions or potentially execute arbitrary code in the context of the objdump process, affecting development environments and build systems.

Affected Products

GNU Binutils versions up to 2.43
Systems and development environments utilizing vulnerable objdump binaries
Build pipelines and CI/CD systems processing untrusted binary files

Discovery Timeline

2025-01-29 - CVE-2025-0840 published to NVD
2025-03-04 - Last updated in NVD database

Technical Details for CVE-2025-0840

Vulnerability Analysis

This vulnerability is a classic stack-based buffer overflow (CWE-787: Out-of-bounds Write) combined with improper restriction of operations within the bounds of a memory buffer (CWE-119). The flaw resides in the disassemble_bytes function within binutils/objdump.c, a core component of the GNU Binutils suite used for examining and manipulating binary object files.

The objdump utility is widely used by developers, reverse engineers, and build systems to inspect compiled binaries, display assembly code, and analyze object file structures. The vulnerability can be triggered when processing specially crafted binary files, making it relevant in scenarios where untrusted object files are analyzed.

While the attack vector is network-based, the high complexity of exploitation significantly reduces the practical risk. An attacker would need to craft a malicious binary file and convince a user or automated system to process it with the vulnerable objdump utility.

Root Cause

The root cause of this vulnerability is improper bounds checking when handling the buf argument in the disassemble_bytes function. When processing certain malformed or maliciously crafted input data, the function fails to properly validate buffer boundaries before writing data, resulting in a stack-based buffer overflow condition. This type of memory safety issue is common in C codebases that perform manual memory management without adequate input validation.

Attack Vector

The attack can be initiated remotely through the following general scenario:

An attacker crafts a malicious object file or binary with specially designed content targeting the buffer overflow
The victim processes the malicious file using the objdump utility
The disassemble_bytes function processes the crafted input, triggering the overflow
Depending on exploitation, this could result in denial of service or potentially code execution

The exploitation is notably difficult due to the high attack complexity. Factors such as ASLR, stack canaries, and the specific conditions required to trigger the overflow make reliable exploitation challenging. The vulnerability proof-of-concept has been disclosed publicly, increasing the importance of patching affected systems.

Detection Methods for CVE-2025-0840

Indicators of Compromise

Unexpected crashes or segmentation faults in objdump processes
Abnormal memory consumption patterns in binutils processes
Core dumps generated by objdump when processing specific binary files
Suspicious object files with malformed section headers or unusual data patterns

Detection Strategies

Monitor for objdump process crashes and analyze core dumps for stack overflow patterns
Implement file integrity monitoring for binutils binaries to detect unauthorized modifications
Use static analysis tools to scan binary files before processing with development tools
Deploy endpoint detection and response (EDR) solutions to monitor process behavior anomalies

Monitoring Recommendations

Enable crash reporting and centralized logging for development and build systems
Audit usage of objdump and other binutils utilities in automated pipelines
Implement sandboxing for processes that analyze untrusted binary files
Review system logs for repeated objdump failures which may indicate exploitation attempts

How to Mitigate CVE-2025-0840

Immediate Actions Required

Upgrade GNU Binutils to version 2.44 or later which contains the security fix
Avoid processing untrusted binary files with objdump until patching is complete
Implement network segmentation to limit exposure of development systems
Enable available exploit mitigations (ASLR, stack canaries) if not already active

Patch Information

The vulnerability has been addressed in GNU Binutils version 2.44. The fix is identified by commit hash baac6c221e9d69335bf41366a1c7d87d8ab2f893 in the binutils-gdb repository. Organizations should upgrade to the patched version as soon as possible. The patch can be reviewed at the Sourceware Git Commit.

Additional technical details are available in the Sourceware Bug Report and the VulDB Entry.

Workarounds

Run objdump in isolated environments or containers when analyzing untrusted files
Use alternative disassembly tools temporarily until patching is complete
Implement strict input validation and file scanning before processing binaries
Restrict access to development tools to authorized personnel only

bash

# Verify current binutils version
objdump --version

# Check if patched version is available in package manager
# For Debian/Ubuntu:
apt-cache policy binutils

# For RHEL/CentOS:
yum info binutils

# Upgrade binutils to patched version (2.44+)
# Debian/Ubuntu:
sudo apt update && sudo apt upgrade binutils

# RHEL/CentOS:
sudo yum update binutils

# Verify upgrade
objdump --version | head -1