CVE-2019-17151 in WeChat
Summary
by MITRE
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Tencent WeChat Prior to 7.0.9. User interaction is required to exploit this vulnerability in that the target must be within a chat session together with the attacker. The specific flaw exists within the parsing of a usernames. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-9302.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 03/20/2024
The vulnerability identified as CVE-2019-17151 represents a critical remote code execution flaw in Tencent WeChat versions prior to 7.0.9. This security weakness operates within the chat session context where user interaction is mandatory for exploitation, making it a targeted attack vector rather than a fully autonomous threat. The vulnerability stems from insufficient input validation mechanisms during the processing of username data, creating an environment where maliciously crafted user-supplied strings can be leveraged to execute arbitrary commands on affected systems. The flaw specifically manifests in the parsing logic for usernames, where the application fails to properly sanitize or validate user input before incorporating it into system-level operations.
From a technical perspective, this vulnerability maps to CWE-78 which describes improper neutralization of special elements used in OS commands, commonly referred to as OS command injection. The flaw allows attackers to inject malicious commands through the username parsing mechanism, effectively bypassing normal security boundaries. The vulnerability's exploitation requires the attacker to be in a chat session with the target, aligning with the ATT&CK technique T1190 - Exploit Public-Facing Application, where adversaries leverage vulnerabilities in accessible services to gain unauthorized access. The attack chain begins with the attacker initiating communication within a chat session, then crafting a malicious username that when processed by WeChat's vulnerable parsing logic, triggers a system call with elevated privileges.
The operational impact of this vulnerability extends beyond simple code execution, as it allows attackers to operate within the context of the current process, potentially gaining access to sensitive user data, chat histories, and communication metadata. The vulnerability affects a significant user base given WeChat's widespread adoption in China and international markets, making it particularly attractive to threat actors seeking large-scale exploitation opportunities. The requirement for user interaction in the attack vector provides some defense-in-depth characteristics, as users may recognize suspicious behavior in chat sessions, though this protection is not foolproof. The vulnerability's classification as a remote code execution flaw means that attackers can potentially establish persistent access, exfiltrate data, or deploy additional malware on compromised systems without requiring physical access or local privileges.
Mitigation strategies for CVE-2019-17151 should prioritize immediate patching of WeChat installations to version 7.0.9 or later, which contains the necessary fixes for the username parsing validation. Organizations should implement network monitoring to detect unusual chat session behavior and potential exploitation attempts, particularly focusing on communication patterns that might indicate malicious username injection attempts. Security teams should also consider implementing user education programs to raise awareness about the risks of interacting with unknown or untrusted users in chat applications, as the vulnerability requires user participation in the attack. Additional defensive measures include network segmentation to limit chat application access, implementing application whitelisting policies to restrict execution of unauthorized code, and conducting regular security assessments of messaging applications within the enterprise environment. The vulnerability's nature suggests that attackers might also attempt to exploit similar issues in other messaging platforms, making broader security hygiene practices essential for protecting against related threats.