CVE-2007-2797 in xterm
Summary
by MITRE
xterm, including 192-7.el4 in Red Hat Enterprise Linux and 208-3.1 in Debian GNU/Linux, sets the wrong group ownership of tty devices, which allows local users to write data to other users terminals.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability described in CVE-2007-2797 affects xterm terminal emulator implementations across multiple Linux distributions including Red Hat Enterprise Linux and Debian GNU/Linux. This security flaw resides in the improper handling of terminal device ownership during the initialization process of xterm applications. The vulnerability specifically impacts how xterm manages the group ownership of tty devices, creating a privilege escalation scenario that undermines the fundamental security model of Unix-like systems.
The technical flaw manifests when xterm fails to correctly set the group ownership of terminal devices it creates or manages. In normal operation, terminal devices should be owned by the appropriate group to prevent unauthorized access and data injection by malicious local users. However, due to this implementation error, xterm sets incorrect group permissions on tty devices, allowing users who do not normally have access to another user's terminal to write data directly to those terminals. This misconfiguration creates a direct pathway for information disclosure and potential session hijacking attacks.
The operational impact of this vulnerability extends beyond simple privilege escalation as it enables malicious users to inject data into other users' terminal sessions, potentially leading to credential theft, session manipulation, or information disclosure. Attackers can exploit this weakness to monitor or interfere with active terminal sessions, particularly in multi-user environments where users share system resources. The vulnerability is particularly dangerous in server environments where multiple users may be logged in simultaneously, as it allows for covert data injection into active sessions without detection.
This vulnerability maps to CWE-276, which describes improper file permissions, and relates to the broader category of privilege escalation flaws within Unix-like systems. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and credential access, specifically targeting the T1068 (Local Privilege Escalation) and T1552 (Credentials in Files) tactics. The flaw represents a classic case of improper access control implementation that violates the principle of least privilege, allowing unauthorized users to bypass normal terminal security boundaries.
Mitigation strategies for this vulnerability require immediate system updates and patches from the respective distribution vendors. System administrators should ensure that all xterm installations are updated to versions that properly handle tty device group ownership. Additionally, implementing proper monitoring of terminal device access patterns can help detect potential exploitation attempts. The recommended approach includes applying security patches promptly, reviewing system configurations for proper terminal device permissions, and implementing network segmentation to limit potential attack vectors. Regular security audits of terminal emulator configurations should also be conducted to prevent similar issues from arising in other system components.