CVE-2021-26624 in eScan Anti-Virus
Summary
by MITRE • 04/02/2022
An local privilege escalation vulnerability due to a "runasroot" command in eScan Anti-Virus. This vulnerability is due to invalid arguments and insufficient execution conditions related to "runasroot" command. This vulnerability can induce remote attackers to exploit root privileges by manipulating parameter values.
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Analysis
by VulDB Data Team • 04/05/2022
The vulnerability identified as CVE-2021-26624 represents a critical local privilege escalation flaw within the eScan Anti-Virus security solution. This weakness stems from improper handling of the "runasroot" command functionality, which is designed to execute specific operations with elevated privileges. The vulnerability manifests when the system fails to properly validate input arguments passed to this privileged execution mechanism, creating a pathway for malicious actors to manipulate parameter values and gain unauthorized root access. The flaw exists at the command execution layer where insufficient validation controls allow attackers to craft specially crafted inputs that bypass normal privilege restrictions.
The technical implementation of this vulnerability aligns with CWE-787, representing an out-of-bounds write condition that occurs when the "runasroot" command processes invalid arguments without proper bounds checking. This weakness creates a direct attack surface where parameter manipulation can lead to privilege escalation, as the system does not adequately verify the legitimacy of input values before executing privileged operations. The insufficient execution conditions referenced in the vulnerability description indicate that the system lacks proper authorization checks and validation mechanisms that should occur before any elevated privilege operations are initiated. Attackers can exploit this by carefully crafting command line parameters or environment variables that cause the "runasroot" function to execute with root privileges under unintended circumstances, effectively bypassing the normal access control mechanisms that should prevent such unauthorized privilege elevation.
From an operational impact perspective, this vulnerability presents a severe threat to systems running eScan Anti-Virus, as successful exploitation allows attackers to gain complete root access to the affected machine. The implications extend beyond simple privilege escalation, as root access provides unrestricted control over system resources, file access, and the ability to install malicious software or modify critical system components. This vulnerability particularly affects enterprise environments where antivirus solutions are widely deployed, as it could enable attackers to establish persistent backdoors or exfiltrate sensitive data from within the network perimeter. The remote exploitation capability mentioned in the description suggests that attackers may be able to leverage this vulnerability from outside the local network, potentially expanding the attack surface significantly.
Security practitioners should implement immediate mitigations including updating to the latest version of eScan Anti-Virus that addresses this vulnerability, disabling unnecessary privileged execution features when possible, and implementing strict input validation controls for all command execution interfaces. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting T1068 which covers 'Exploitation for Privilege Escalation' and T1548 which covers 'Abuse Elevation Control Mechanism'. Organizations should conduct thorough vulnerability assessments to identify systems running vulnerable versions of eScan, implement network segmentation to limit potential lateral movement, and establish monitoring procedures to detect suspicious command execution patterns that might indicate exploitation attempts. The vulnerability also highlights the importance of proper privilege separation and input validation in security-critical applications, emphasizing the need for defense-in-depth strategies that protect against such fundamental access control bypass mechanisms.