CVE-2019-1798 in ClamAV
Summary
by MITRE
A vulnerability in the Portable Executable (PE) file scanning functionality of Clam AntiVirus (ClamAV) Software versions 0.101.1 and prior could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to a lack of proper input and validation checking mechanisms for PE files sent an affected device. An attacker could exploit this vulnerability by sending malformed PE files to the device running an affected version ClamAV Software. An exploit could allow the attacker to cause an out-of-bounds read condition, resulting in a crash that could result in a denial of service condition on an affected device.
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Analysis
by VulDB Data Team • 08/27/2023
The vulnerability identified as CVE-2019-1798 affects Clam AntiVirus software versions 0.101.1 and earlier, specifically within the Portable Executable file scanning functionality. This represents a critical security flaw that undermines the integrity of endpoint protection systems. The vulnerability stems from insufficient input validation mechanisms when processing PE files, which are the standard executable file format used on Windows operating systems. When ClamAV encounters PE files during scanning operations, it fails to properly validate the structure and content of these files before attempting to parse them, creating an exploitable condition that can be leveraged by malicious actors.
The technical exploitation of this vulnerability occurs through the delivery of malformed PE files to systems running affected ClamAV versions. The flaw manifests as an out-of-bounds read condition, where the software attempts to access memory locations beyond the allocated buffer boundaries when processing corrupted or specially crafted PE file structures. This memory access violation triggers a segmentation fault or similar crash condition that terminates the ClamAV scanning process. The vulnerability is particularly concerning because it can be exploited remotely without authentication requirements, making it accessible to attackers who may not have direct system access. This type of flaw falls under CWE-129, Input Validation, and specifically relates to improper validation of input data structures.
The operational impact of CVE-2019-1798 extends beyond simple service disruption, as it can compromise the overall security posture of affected systems. When the ClamAV service crashes due to this vulnerability, it creates a window of opportunity for attackers to bypass security protections during the time when the antivirus software is unavailable. Organizations relying on ClamAV for endpoint protection face significant risk of continued malware infections during the service outage period. The vulnerability's remote exploitability means that attackers can potentially target multiple systems simultaneously through network-based attacks, amplifying the potential damage. From an attacker's perspective, this represents a low-effort, high-impact vector that aligns with ATT&CK technique T1499.004, Network Denial of Service, allowing for sustained disruption of security services.
Mitigation strategies for CVE-2019-1798 primarily focus on immediate software updates to versions that have patched the input validation issues. Organizations should prioritize upgrading ClamAV to version 0.101.2 or later, where the PE file parsing logic has been corrected to properly validate input structures. Additionally, network administrators should implement additional protective measures including the deployment of network-based intrusion detection systems that can identify and block suspicious PE file patterns before they reach vulnerable systems. The vulnerability highlights the importance of robust input validation in security software, particularly in components that process untrusted data from external sources. System administrators should also consider implementing redundant security measures and monitoring for unusual service termination patterns that may indicate exploitation attempts. Regular security assessments and vulnerability scanning should include verification of ClamAV versions to prevent similar issues from persisting across organizational infrastructure.