CVE-2024-11477 in 7-Zip
Summary
by MITRE • 11/23/2024
7-Zip Zstandard Decompression Integer Underflow Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of 7-Zip. Interaction with this library is required to exploit this vulnerability but attack vectors may vary depending on the implementation.
The specific flaw exists within the implementation of Zstandard decompression. The issue results from the lack of proper validation of user-supplied data, which can result in an integer underflow before writing to memory. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-24346.
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Analysis
by VulDB Data Team • 02/23/2025
The vulnerability identified as CVE-2024-11477 represents a critical integer underflow flaw within the Zstandard decompression implementation of 7-Zip software. This issue manifests when processing compressed data streams that have been manipulated by an attacker, creating conditions where arithmetic operations result in values that fall below the minimum representable integer, leading to unpredictable behavior in memory management operations. The vulnerability specifically affects versions of 7-Zip that utilize the Zstandard compression library for decompressing data, making it particularly concerning given the widespread adoption of 7-Zip across enterprise and consumer environments for file archiving and compression tasks. The integer underflow occurs during the decompression process when the software fails to properly validate the length parameters of compressed data streams, particularly in scenarios where the decompression algorithm attempts to calculate buffer sizes or iteration counts based on attacker-controlled values.
The technical exploitation of this vulnerability requires an attacker to craft specially malformed Zstandard compressed files that trigger the integer underflow condition during decompression operations. When 7-Zip processes such malicious input, the underflow causes memory allocation calculations to produce incorrect values, potentially leading to buffer overflows, memory corruption, or other memory safety violations that can be leveraged for code execution. The vulnerability's remote code execution capability stems from the fact that 7-Zip's decompression functionality is often invoked automatically by operating systems or applications when users open archive files, creating attack vectors through email attachments, download files, or web-based archive access. This scenario aligns with ATT&CK technique T1059.007 for command and scripting interpreter execution, as successful exploitation would allow attackers to execute arbitrary code within the context of the 7-Zip process, potentially leading to privilege escalation or system compromise. The vulnerability is categorized under CWE-191 Integer Underflow (Wrap or Wraparound) which specifically addresses situations where integer arithmetic results in values that wrap around to smaller values, creating exploitable conditions.
The operational impact of CVE-2024-11477 extends beyond simple code execution, as it represents a significant threat to system integrity and data confidentiality across environments that rely on 7-Zip for archive management. Organizations using 7-Zip for automated backup processes, software distribution, or file transfer operations face elevated risk since these scenarios often involve processing untrusted archive files without manual verification. The vulnerability's exploitation potential is amplified by the fact that many enterprise systems automatically decompress archives during installation processes or routine file operations, creating numerous potential attack surfaces. System administrators and security professionals must consider the implications of this vulnerability across various deployment scenarios including web servers handling user uploads, email servers processing archive attachments, and automated build systems that extract compressed source code or dependencies. The vulnerability's classification as a remote code execution flaw means that attackers can potentially compromise systems without physical access, making it particularly dangerous in environments with limited network segmentation or insufficient security monitoring. The ZDI-CAN-24346 reference indicates this vulnerability was recognized by the Zero Day Initiative and subsequently assigned a CVE identifier, reflecting its significance in the cybersecurity community and the urgency for remediation.
Mitigation strategies for CVE-2024-11477 should prioritize immediate software updates from 7-Zip vendors, as the primary fix involves patching the decompression library to properly validate integer values and prevent underflow conditions. Organizations should implement network monitoring to detect suspicious archive file processing activities and consider restricting automatic decompression of archives from untrusted sources. Security teams should deploy application whitelisting policies that restrict execution of 7-Zip components in contexts where untrusted input might be processed, aligning with ATT&CK technique T1134 for access token manipulation and process injection prevention. Additional protective measures include implementing sandboxing for archive processing operations, deploying file integrity monitoring solutions to detect modification of 7-Zip binaries, and establishing incident response procedures specifically for handling potential exploitation attempts. Organizations should also consider implementing automated vulnerability scanning that specifically targets 7-Zip installations and monitors for the presence of vulnerable versions. The remediation process must account for the widespread use of 7-Zip across different platforms and deployment scenarios, requiring coordinated patch management across desktop environments, server infrastructure, and cloud-based systems where archive processing occurs. Security awareness training should emphasize the importance of verifying archive sources and avoiding automatic decompression of untrusted files, particularly in environments where social engineering attacks might be employed to deliver malicious compressed content.