CVE-2020-37095 in Authentication Client
Summary
by MITRE • 02/07/2026
Cyberoam Authentication Client 2.1.2.7 contains a buffer overflow vulnerability that allows remote attackers to execute arbitrary code by overwriting Structured Exception Handler (SEH) memory. Attackers can craft a malicious input in the 'Cyberoam Server Address' field to trigger a bind TCP shell on port 1337 with system-level access.
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Analysis
by VulDB Data Team • 02/07/2026
The vulnerability identified as CVE-2020-37095 represents a critical buffer overflow flaw within the Cyberoam Authentication Client version 2.1.2.7 which operates under the common weakness enumeration CWE-121. This security defect resides in the client application's handling of user-supplied input within the 'Cyberoam Server Address' field, creating an exploitable condition that enables remote code execution. The flaw manifests when the application fails to properly validate the length of input data before copying it into a fixed-size buffer, allowing attackers to overwrite adjacent memory locations including the Structured Exception Handler (SEH) chain.
The technical exploitation of this vulnerability follows a classic stack-based buffer overflow attack pattern where malicious input exceeds the allocated buffer space and overwrites the SEH frame pointer. This memory corruption allows attackers to redirect program execution flow by manipulating the exception handling mechanism, ultimately enabling arbitrary code execution with system-level privileges. The attack vector is particularly concerning as it requires no local access or authentication, making it a remote code execution vulnerability that can be exploited over the network. The vulnerability specifically targets the client application's network communication handling, where it processes server address information during authentication processes.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with full system compromise capabilities through the establishment of a bind TCP shell on port 1337. This shell allows remote attackers to maintain persistent access to the compromised system, execute commands with elevated privileges, and potentially escalate their access to other network resources. The vulnerability affects organizations relying on Cyberoam Authentication Client for network access control, potentially exposing corporate networks to unauthorized access and data exfiltration. The exploitability of this flaw aligns with ATT&CK technique T1059.007 for command and script interpreter, and T1071.004 for application layer protocol, as attackers can leverage the shell to conduct further reconnaissance and lateral movement within the compromised environment.
Organizations should prioritize immediate remediation through vendor-provided security patches or updates addressing the buffer overflow in the Cyberoam Authentication Client. Network segmentation and access controls should be implemented to limit exposure of affected systems, while monitoring for unusual network activity on port 1337 can help detect exploitation attempts. Security teams should also consider implementing application whitelisting policies to prevent execution of unauthorized binaries, and conduct regular vulnerability assessments to identify similar buffer overflow conditions in other network authentication clients. The vulnerability demonstrates the critical importance of proper input validation and memory safety practices in network client applications, particularly those handling user-supplied network configuration parameters.