CVE-2017-12377 in Antivirus Software
Summary
by MITRE
ClamAV AntiVirus software versions 0.99.2 and prior contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition or potentially execute arbitrary code on an affected device. The vulnerability is due to improper input validation checking mechanisms in mew packet files sent to an affected device. A successful exploit could cause a heap-based buffer over-read condition in mew.c when ClamAV scans the malicious file, allowing the attacker to cause a DoS condition or potentially execute arbitrary code on the affected device.
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Analysis
by VulDB Data Team • 02/02/2023
The vulnerability identified as CVE-2017-12377 represents a critical security flaw in ClamAV antivirus software affecting versions 0.99.2 and earlier. This issue stems from inadequate input validation mechanisms within the mew packet file processing functionality, creating a pathway for remote attackers to exploit the system through specially crafted malicious files. The vulnerability resides in the mew.c source file where the software fails to properly validate packet data structures during file scanning operations, leading to potentially catastrophic consequences for affected systems.
The technical exploitation of this vulnerability involves a heap-based buffer over-read condition that occurs when ClamAV processes malicious mew packet files. This type of memory corruption vulnerability allows an attacker to manipulate memory contents beyond allocated boundaries, potentially leading to arbitrary code execution or system instability. The flaw specifically manifests when the software attempts to parse malformed packet data, causing the application to read beyond the intended buffer limits and potentially overwrite critical memory segments. This memory corruption pattern aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a classic example of improper input validation leading to memory safety issues. The vulnerability's classification as a remote attack vector means that exploitation can occur without requiring authentication or physical access to the target system.
The operational impact of CVE-2017-12377 extends beyond simple denial of service conditions to encompass potential system compromise and unauthorized code execution. When an attacker successfully exploits this vulnerability, they can cause the affected ClamAV service to crash or become unresponsive, resulting in a denial of service that disrupts legitimate antivirus scanning operations. More critically, the buffer over-read condition creates opportunities for attackers to inject and execute malicious code within the context of the ClamAV process, potentially escalating privileges and gaining full control over the compromised system. This vulnerability directly affects the integrity and availability of security monitoring systems, creating a dangerous paradox where the security tool itself becomes a potential attack vector. The impact is particularly severe in enterprise environments where ClamAV is widely deployed for email scanning, file system monitoring, and endpoint protection, as a successful exploitation could compromise entire network security infrastructures.
Mitigation strategies for CVE-2017-12377 should prioritize immediate software updates to versions 0.99.3 or later, which contain patches addressing the input validation deficiencies in mew.c. Organizations should implement network segmentation and access controls to limit exposure of ClamAV services to untrusted networks, while also deploying intrusion detection systems to monitor for suspicious packet patterns. The ATT&CK framework categorizes this vulnerability under T1203, which describes exploitation of remote services, making it critical to implement proper network monitoring and endpoint detection capabilities. Additional defensive measures include regular security assessments of antivirus configurations, implementation of file type restrictions for scanning, and maintaining detailed logging of ClamAV operations to detect potential exploitation attempts. System administrators should also consider implementing application whitelisting policies to restrict execution of untrusted files through ClamAV processes, while maintaining regular backup and recovery procedures to ensure rapid restoration in case of successful exploitation. The vulnerability underscores the importance of robust input validation and memory safety practices in security software, particularly in applications that process untrusted data from external sources.