CVE-2007-2846 in avast!
Summary
by MITRE
Heap-based buffer overflow in the SIS unpacker in avast! Anti-Virus Managed Client before 4.7.700 allows user-assisted remote attackers to execute arbitrary code via a crafted SIS archive, resulting from an "integer cast around."
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/13/2025
The vulnerability identified as CVE-2007-2846 represents a critical heap-based buffer overflow in the SIS unpacker component of avast! Anti-Virus Managed Client versions prior to 4.7.700. This flaw exists within the software's handling of SIS (Symbian Installable Software) archives, which are commonly used for distributing applications on Symbian-based mobile devices. The vulnerability arises from an integer cast around issue that occurs during the unpacking process, creating a condition where an attacker can manipulate memory allocation and subsequently execute arbitrary code on the target system. The SIS unpacker functionality is specifically designed to process these mobile application packages, making it a legitimate component that users would interact with when managing mobile device software installations.
The technical root cause of this vulnerability stems from improper handling of integer values during memory allocation calculations within the SIS unpacking routine. When processing a crafted SIS archive, the application performs an integer cast operation that fails to properly validate or constrain the size parameter used for heap allocation. This integer cast around condition allows an attacker to manipulate the intended memory allocation size, causing the application to allocate insufficient memory for the buffer that will eventually contain the decompressed data. The flaw is classified as a heap-based buffer overflow because the insufficiently allocated heap memory leads to memory corruption when the application attempts to write data beyond the allocated buffer boundaries, potentially overwriting adjacent memory structures including return addresses and function pointers.
The operational impact of this vulnerability is significant, as it enables user-assisted remote code execution attacks against systems running vulnerable versions of avast Anti-Virus Managed Client is installed and actively processing SIS archives, making it particularly dangerous in enterprise environments where mobile device management is implemented. The attack requires user interaction to process the malicious archive, but once executed, it provides full code execution capabilities within the context of the antivirus client process.
This vulnerability aligns with CWE-121, which describes heap-based buffer overflow conditions, and demonstrates characteristics consistent with the attack patterns outlined in the MITRE ATT&CK framework under the T1059.007 technique for command and scripting interpreter. The integer cast around issue represents a classic programming error that can be mitigated through proper input validation, bounds checking, and secure coding practices. Organizations should prioritize immediate patching of affected systems to address this vulnerability, as the combination of remote exploitability and code execution capabilities makes it particularly dangerous. The vulnerability also highlights the importance of secure handling of third-party archive formats within security software, as the legitimate functionality of processing mobile application packages becomes a potential attack surface when proper memory management practices are not implemented. Security professionals should implement monitoring for suspicious SIS file processing activities and ensure that all antivirus and security software components are regularly updated to address similar vulnerabilities in archive handling functionality.