CVE-2022-35113 in SWFTools
Summary
by MITRE • 08/17/2022
SWFTools commit 772e55a2 was discovered to contain a heap-buffer overflow via swf_DefineLosslessBitsTagToImage at /modules/swfbits.c.
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Analysis
by VulDB Data Team • 08/17/2022
The vulnerability identified as CVE-2022-35113 represents a critical heap-buffer overflow condition within SWFTools, specifically manifesting in the swf_DefineLosslessBitsTagToImage function located at /modules/swfbits.c. This issue arises from improper input validation and memory management when processing swf files containing DefineLosslessBitsTag data structures. The flaw exists in the software development toolkit designed for manipulating flash files and handling swf content, making it particularly concerning for organizations that process or convert flash-based multimedia content. The vulnerability stems from the library's inability to properly validate the size of incoming data buffers before performing memory operations, creating an exploitable condition that could be leveraged by malicious actors.
The technical implementation of this heap-buffer overflow occurs when the swf_DefineLosslessBitsTagToImage function processes image data within swf files. The function fails to validate the expected size of the lossless bits data against the actual buffer boundaries, allowing attackers to craft specially malformed swf files that trigger memory corruption. When the application attempts to read or write beyond allocated heap memory boundaries, it creates opportunities for arbitrary code execution or system instability. This vulnerability specifically relates to CWE-121, heap-based buffer overflow, where insufficient boundary checking leads to memory corruption. The issue is particularly dangerous because it can be triggered through normal file processing operations, making it an attractive target for remote exploitation.
Operationally, this vulnerability presents significant risks to organizations that rely on SWFTools for processing flash content, including media companies, educational institutions, and web developers who handle swf file conversions or manipulations. An attacker could exploit this vulnerability by uploading or processing a maliciously crafted swf file, potentially leading to complete system compromise or denial of service conditions. The impact extends beyond individual system compromise to include potential data exfiltration and persistent access within network environments. This vulnerability aligns with ATT&CK technique T1203, Exploitation for Client Execution, as it enables attackers to execute arbitrary code on systems processing vulnerable swf content through legitimate software interfaces.
Mitigation strategies for CVE-2022-35113 should prioritize immediate patching of affected SWFTools installations to address the heap-buffer overflow condition. Organizations should implement strict input validation for all swf file processing operations, including size checking and boundary validation for lossless bits data structures. Network segmentation and access controls should be enforced to limit exposure of systems processing swf content, while regular security assessments should monitor for similar vulnerabilities in related software libraries. Additionally, implementing sandboxing mechanisms for swf file processing and deploying intrusion detection systems to monitor for exploitation attempts can provide defense-in-depth protection. The vulnerability demonstrates the importance of maintaining up-to-date software libraries and implementing comprehensive security testing procedures for all file processing components within multimedia applications.