CVE-2024-48958: Libarchive Buffer Overflow Vulnerability

CVE-2024-48958 Overview

CVE-2024-48958 is an out-of-bounds read vulnerability affecting the execute_filter_delta function in archive_read_support_format_rar.c within libarchive versions prior to 3.7.5. The vulnerability occurs when processing specially crafted RAR archive files, where the source pointer (src) can move beyond the destination buffer (dst), resulting in out-of-bounds memory access.

Libarchive is a widely-used open-source library that provides streaming archive reading and writing capabilities for various archive formats including tar, cpio, pax, zip, and RAR. This vulnerability specifically affects RAR format processing and can be triggered when a user or application processes a malicious archive file.

Critical Impact

Successful exploitation of this vulnerability could allow attackers to read sensitive memory contents or cause application crashes through out-of-bounds memory access when processing maliciously crafted RAR archives.

Affected Products

• libarchive versions prior to 3.7.5
• Applications and systems that utilize libarchive for RAR archive processing
• Operating systems and tools bundled with vulnerable libarchive versions (including macOS and iOS)

Discovery Timeline

• October 10, 2024 - CVE-2024-48958 published to NVD
• November 03, 2025 - Last updated in NVD database

Technical Details for CVE-2024-48958

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), occurring within the delta filter execution routine used during RAR archive decompression. The execute_filter_delta function in libarchive's RAR format support code contains a boundary condition error that fails to properly validate pointer arithmetic operations.

During delta filter processing, the function manipulates source and destination pointers to perform data transformations. The vulnerability manifests when the source pointer advances beyond the bounds of the destination buffer, allowing read operations to access memory outside the intended allocation. This can occur when processing archives containing specially crafted filter parameters that manipulate the relationship between src and dst pointers.

The local attack vector requires user interaction, meaning an attacker must convince a victim to open or process a malicious RAR archive file. Once triggered, the vulnerability can result in information disclosure through memory content exposure or denial of service through application crashes.

Root Cause

The root cause of CVE-2024-48958 lies in insufficient bounds checking within the execute_filter_delta function. The delta filter implementation fails to properly validate that the source pointer remains within valid memory boundaries relative to the destination buffer during filter operations. This allows crafted archive data to manipulate pointer positions, causing the source pointer to advance beyond the destination buffer's allocated memory region.

Attack Vector

An attacker can exploit this vulnerability by crafting a malicious RAR archive file containing specially designed filter parameters. The attack scenario involves:

1. Creating a RAR archive with manipulated delta filter data that causes improper pointer arithmetic
2. Distributing the malicious archive through email attachments, file sharing, or compromised download sources
3. Triggering the vulnerability when the victim's application uses libarchive to extract or inspect the archive contents
4. Gaining access to out-of-bounds memory contents or causing the application to crash

The vulnerability requires local access to deliver the malicious file and user interaction to process it, limiting the attack surface compared to network-based exploits.

The vulnerability occurs in the delta filter processing routine where insufficient validation allows the src pointer to exceed dst boundaries. The fix implemented in version 3.7.5 adds proper bounds checking to prevent the out-of-bounds access. Technical details of the patch can be found in the GitHub Pull Request #2148.

Detection Methods for CVE-2024-48958

Indicators of Compromise

• Unexpected application crashes or segmentation faults when processing RAR archives
• Memory access violations logged in system or application error logs
• Anomalous behavior in applications utilizing libarchive for archive operations
• Presence of unusually structured RAR archives with malformed delta filter parameters

Detection Strategies

• Implement file integrity monitoring for libarchive library files to detect unauthorized modifications
• Deploy endpoint detection rules to identify applications crashing due to out-of-bounds memory access patterns
• Monitor for suspicious RAR files with abnormal header structures or filter configurations
• Utilize static analysis tools to scan for vulnerable libarchive versions in deployed applications

Monitoring Recommendations

• Enable verbose logging for applications that process archive files to capture error conditions
• Configure crash dump analysis to identify exploitation attempts through memory corruption patterns
• Implement network monitoring to detect delivery of potentially malicious RAR archives
• Use software composition analysis tools to inventory libarchive usage across the environment

How to Mitigate CVE-2024-48958

Immediate Actions Required

• Upgrade libarchive to version 3.7.5 or later immediately
• Audit all systems and applications for vulnerable libarchive versions
• Implement input validation for archive files before processing
• Consider temporarily disabling RAR archive processing if patching is not immediately feasible

Patch Information

The vulnerability has been addressed in libarchive version 3.7.5. The fix implements proper bounds checking in the execute_filter_delta function to prevent the source pointer from exceeding destination buffer boundaries. Organizations should update to the patched version through their package manager or by compiling from the official libarchive repository.

The patch details can be reviewed in the GitHub comparison between v3.7.4 and v3.7.5. Additional technical information about the fix is available in GitHub Pull Request #2148.

Workarounds

• Restrict processing of RAR archives from untrusted sources until patching is complete
• Implement application sandboxing to limit the impact of potential memory corruption
• Deploy web and email filtering to block potentially malicious RAR attachments
• Use alternative archive processing libraries that do not share the vulnerable code path

# Check installed libarchive version
pkg-config --modversion libarchive

# Update libarchive on Debian/Ubuntu systems
sudo apt update && sudo apt upgrade libarchive-dev

# Update libarchive on RHEL/CentOS systems
sudo yum update libarchive

# Update libarchive on macOS via Homebrew
brew update && brew upgrade libarchive