CVE-2022-48622: Gnome GdkPixbuf RCE Vulnerability

CVE-2022-48622 Overview

CVE-2022-48622 is a heap memory corruption vulnerability affecting GNOME GdkPixbuf (gdk-pixbuf) through version 2.42.10. The vulnerability exists in the ANI (Windows animated cursor) decoder within the ani_load_chunk function in io-ani.c. When parsing chunks in a specially crafted .ani file, an attacker can trigger heap memory corruption that overwrites heap metadata. This can lead to denial of service or potentially enable arbitrary code execution. The vulnerability specifically manifests in the gdk_pixbuf_set_option() function in gdk-pixbuf.c.

Critical Impact

A crafted ANI file can corrupt heap memory, allowing attackers to overwrite heap metadata and potentially achieve code execution on systems running vulnerable versions of GdkPixbuf.

Affected Products

• GNOME GdkPixbuf through version 2.42.10
• Linux distributions and applications utilizing GdkPixbuf for image processing
• Desktop environments and applications that render Windows animated cursor files

Discovery Timeline

• 2024-01-26 - CVE CVE-2022-48622 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2022-48622

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-Bounds Write), a critical memory corruption issue that occurs during the parsing of Windows animated cursor (ANI) files. GdkPixbuf is a widely-used image loading library in the GNOME ecosystem, making this vulnerability potentially impactful across numerous Linux desktop environments and applications.

The flaw resides in the ANI decoder's chunk parsing logic within io-ani.c. When processing malformed or crafted ANI files, the decoder fails to properly validate chunk boundaries or sizes before writing data to heap-allocated memory. This improper bounds checking allows an attacker to corrupt adjacent heap metadata structures.

The vulnerability requires local access and user interaction—specifically, a user must open or preview a malicious ANI file. However, given that image previews are often automatically generated by file managers and desktop environments, the attack surface extends to scenarios where users simply browse directories containing malicious files.

Root Cause

The root cause lies in insufficient input validation within the ani_load_chunk function. When parsing ANI file chunks, the decoder does not adequately verify that chunk sizes and offsets remain within allocated buffer boundaries. This allows specially crafted chunk data to write beyond the intended memory region.

The corruption ultimately occurs in gdk_pixbuf_set_option() within gdk-pixbuf.c, where improperly validated data from the ANI parser is used to modify heap structures without proper boundary enforcement.

Attack Vector

The attack vector is local, requiring an attacker to deliver a crafted .ani file to the target system. Exploitation scenarios include:

• Distributing malicious ANI files via email attachments or downloads
• Placing crafted files in shared directories where automatic thumbnail generation triggers the vulnerable code path
• Embedding malicious cursor resources in applications or archives

The vulnerability exploits heap memory corruption by crafting ANI file chunks with specific size and offset values designed to overwrite heap metadata structures. Successful exploitation could allow an attacker to gain control of heap allocations, potentially leading to arbitrary code execution with the privileges of the application processing the file.

For detailed technical information about the vulnerability mechanism and affected code paths, refer to the GNOME gdk-pixbuf Issue tracking this vulnerability.

Detection Methods for CVE-2022-48622

Indicators of Compromise

• Presence of suspicious or unexpected .ani files on the system, particularly in user download directories or temporary folders
• Application crashes or segmentation faults in processes utilizing GdkPixbuf when accessing image files
• Unusual memory access patterns or heap corruption errors logged by system monitoring tools
• Unexpected child processes spawned by image-processing applications

Detection Strategies

• Monitor for crashes in applications using GdkPixbuf libraries, particularly those involving ANI file processing
• Implement file integrity monitoring on systems processing untrusted image files
• Deploy endpoint detection solutions capable of identifying heap spray and memory corruption exploitation techniques
• Use application sandboxing to isolate image processing operations and detect anomalous behavior

Monitoring Recommendations

• Enable core dump collection and analysis for applications utilizing GdkPixbuf to identify exploitation attempts
• Implement logging for file access events involving .ani files from untrusted sources
• Monitor system calls for unusual memory allocation patterns associated with image processing applications
• Configure SentinelOne behavioral AI to detect memory corruption exploitation patterns in desktop applications

How to Mitigate CVE-2022-48622

Immediate Actions Required

• Update GdkPixbuf to the latest patched version available from your distribution's package repositories
• Restrict processing of ANI files from untrusted sources until patches are applied
• Configure file type restrictions to block or quarantine .ani files at email gateways and file sharing services
• Enable application sandboxing for image viewing and file management applications

Patch Information

Organizations should update to patched versions of GdkPixbuf as they become available from GNOME and downstream distribution maintainers. Monitor the GNOME gdk-pixbuf issue tracker for patch availability and updated releases. Linux distribution security advisories should be consulted for distribution-specific package updates.

Workarounds

• Disable ANI file support in GdkPixbuf by removing or renaming the io-ani.so loader module until patches can be applied
• Implement content filtering to block ANI files at network perimeters and email gateways
• Use file type validation to prevent automatic processing of ANI files in file managers and preview generators
• Run applications that process untrusted images in sandboxed or containerized environments with restricted permissions

# Disable ANI loader module as a temporary workaround
# Location may vary by distribution
sudo mv /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ani.so /usr/lib/x86_64-linux-gnu/gdk-pixbuf-2.0/2.10.0/loaders/libpixbufloader-ani.so.disabled

# Update the GdkPixbuf loader cache after removing the module
sudo gdk-pixbuf-query-loaders --update-cache