CVE-2023-52168: 7-Zip NTFS Handler Buffer Overflow Flaw

CVE-2023-52168 Overview

CVE-2023-52168 is a heap-based buffer overflow vulnerability in the NTFS handler component (NtfsHandler.cpp) of 7-Zip, a widely-used file archiver utility. The vulnerability allows an attacker to overwrite two bytes at multiple offsets beyond the allocated buffer size, following a predictable pattern of buffer+512*i-2 for i=9, i=10, i=11, and subsequent values. This memory corruption vulnerability affects 7-Zip versions prior to 24.01 and could potentially be exploited to achieve arbitrary code execution or cause application crashes.

Critical Impact

This heap-based buffer overflow in 7-Zip's NTFS handler can allow attackers to corrupt heap memory with controlled two-byte overwrites at predictable offsets, potentially leading to code execution or denial of service when processing maliciously crafted NTFS images.

Affected Products

• 7-Zip versions before 24.01
• 7zz (7-Zip for Linux/Unix) versions before 24.01
• Applications and systems utilizing vulnerable 7-Zip libraries for NTFS handling

Discovery Timeline

• 2024-07-03 - CVE-2023-52168 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2023-52168

Vulnerability Analysis

The vulnerability resides in the NtfsHandler.cpp file, which is responsible for parsing and extracting content from NTFS file system images within 7-Zip archives. The flaw manifests as a CWE-122 (Heap-based Buffer Overflow) where improper boundary validation during NTFS record processing allows writes beyond the allocated buffer boundaries.

The overflow occurs in a loop construct where the handler processes NTFS data structures. At each iteration, two bytes are written at a calculated offset following the pattern buffer+512*i-2. When the loop counter i reaches values of 9 and beyond, these writes extend past the legitimate buffer allocation, corrupting adjacent heap memory. This predictable overflow pattern means an attacker can potentially craft input that overwrites specific heap metadata or adjacent objects.

The local attack vector requires a user to open or extract a maliciously crafted archive containing a specially constructed NTFS image. No user interaction beyond opening the file is required once the target engages with the malicious archive.

Root Cause

The root cause is insufficient boundary checking in the NTFS handler's parsing logic. When iterating through NTFS data records at 512-byte intervals, the code fails to verify that write operations at buffer+512*i-2 remain within the allocated buffer bounds. The offset calculation assumes a maximum number of iterations that doesn't account for maliciously crafted NTFS structures with excessive record counts, leading to heap corruption when processing oversized or malformed NTFS images.

Attack Vector

The attack requires local access, meaning an attacker must deliver a malicious archive file to the victim. This can be accomplished through various social engineering techniques such as email attachments, malicious downloads, or compromised file sharing services. When a user attempts to open, preview, or extract the contents of a maliciously crafted archive containing a specially constructed NTFS image using a vulnerable version of 7-Zip, the heap overflow is triggered.

The two-byte overwrites at predictable offsets could potentially be chained to:

• Corrupt heap metadata, leading to arbitrary write primitives
• Overwrite function pointers in adjacent heap objects
• Cause denial of service through heap corruption crashes

For detailed technical analysis of this vulnerability, see the DFIR Analysis on 7-Zip Vulnerabilities and the SourceForge Bug Report #2402.

Detection Methods for CVE-2023-52168

Indicators of Compromise

• Unexpected crashes in 7-Zip processes (7z.exe, 7zz, 7zFM.exe) when opening archive files
• Archive files containing NTFS images with anomalously large or malformed record structures
• Heap corruption error messages or segmentation faults during archive extraction
• Suspicious archive files received via email or downloaded from untrusted sources

Detection Strategies

• Monitor for 7-Zip process crashes or abnormal terminations that may indicate exploitation attempts
• Implement file scanning rules to detect archives containing potentially malicious NTFS images with oversized structures
• Deploy endpoint detection solutions capable of identifying heap corruption attack patterns
• Use application allow-listing to prevent unauthorized archive utilities from executing

Monitoring Recommendations

• Enable detailed logging for 7-Zip operations and monitor for extraction failures
• Track software inventory to identify systems running vulnerable 7-Zip versions (prior to 24.01)
• Configure security information and event management (SIEM) to alert on repeated 7-Zip crashes
• Monitor network traffic for archive files from untrusted external sources

How to Mitigate CVE-2023-52168

Immediate Actions Required

• Upgrade 7-Zip to version 24.01 or later immediately across all systems
• Implement endpoint protection to detect and block exploitation attempts targeting this vulnerability
• Restrict archive extraction permissions to trusted sources and sandboxed environments
• Educate users about the risks of opening archives from unknown or untrusted sources

Patch Information

The vulnerability has been addressed in 7-Zip version 24.01. Users should download the latest version from the official 7-Zip website or through trusted package managers. For systems using 7-Zip libraries, ensure all dependent applications are updated to use the patched library version.

Additional vendor advisory information is available from NetApp Security Advisory NTAP-20241122-0011 for affected NetApp products.

Workarounds

• Avoid opening NTFS images or archives containing NTFS file systems from untrusted sources until patched
• Use alternative archive utilities that do not have this vulnerability for processing NTFS images
• Implement sandboxing solutions to isolate 7-Zip operations from critical system components
• Configure email gateways to scan or quarantine archive attachments containing NTFS images

# Check current 7-Zip version and upgrade if necessary
# On Windows (PowerShell)
# Get-Command 7z.exe | Select-Object -ExpandProperty Version

# On Linux, check 7zz version
7zz --help | head -n 3

# Update via package manager (example for Debian/Ubuntu)
# sudo apt update && sudo apt install 7zip

# Verify version is 24.01 or later after update