CVE-2003-1090 in AbsoluteTelnet
Summary
by MITRE
Buffer overflow in AbsoluteTelnet before 2.12 RC10 allows remote attackers to execute arbitrary code via a long window title.
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Analysis
by VulDB Data Team • 02/23/2025
The vulnerability described in CVE-2003-1090 represents a critical buffer overflow flaw affecting AbsoluteTelnet software versions prior to 2.12 RC10. This issue resides within the window title handling mechanism of the telnet client implementation, where insufficient input validation allows malicious actors to craft specially formatted window titles that exceed the allocated buffer space. The flaw specifically targets the client-side application rather than the server component, making it particularly dangerous as it can be exploited through remote connections to vulnerable systems.
The technical implementation of this buffer overflow occurs when the AbsoluteTelnet application processes window title strings received from remote servers or configured by users. The software fails to properly bounds-check the length of window title data before copying it into a fixed-size memory buffer, creating an exploitable condition where adjacent memory regions can be overwritten. This classic buffer overflow vulnerability enables attackers to manipulate program execution flow by overwriting return addresses, function pointers, or other critical control data structures within the application's memory space. The vulnerability aligns with CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows memory access beyond allocated buffer boundaries.
From an operational perspective, this vulnerability presents significant risk to organizations relying on AbsoluteTelnet for remote system administration and network connectivity. Attackers can exploit this flaw remotely by establishing telnet connections to vulnerable systems and sending maliciously crafted window title data that triggers the buffer overflow condition. Successful exploitation can result in arbitrary code execution with the privileges of the affected application process, potentially leading to complete system compromise. The remote nature of the attack means that defenders cannot rely on local network controls to prevent exploitation, as the vulnerability can be triggered from any location with network access to the vulnerable telnet service.
The impact extends beyond simple code execution to encompass broader security implications including privilege escalation, data compromise, and potential lateral movement within networks. Organizations using older versions of AbsoluteTelnet face heightened risk as this vulnerability has existed since 2003 and was not widely patched in many deployments. The flaw demonstrates the importance of maintaining up-to-date security patches and proper input validation in client applications, particularly those handling untrusted network data. Security professionals should consider this vulnerability in the context of ATT&CK framework's execution techniques, particularly those involving code injection and privilege escalation methods that leverage buffer overflow conditions to gain unauthorized access to systems and execute malicious payloads with elevated privileges.