CVE-2008-2383 in xterm
Summary
by MITRE
CRLF injection vulnerability in xterm allows user-assisted attackers to execute arbitrary commands via LF (aka \n) characters surrounding a command name within a Device Control Request Status String (DECRQSS) escape sequence in a text file, a related issue to CVE-2003-0063 and CVE-2003-0071.
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Analysis
by VulDB Data Team • 02/03/2025
The CVE-2008-2383 vulnerability represents a critical CRLF injection flaw in the xterm terminal emulator that enables user-assisted attackers to execute arbitrary commands through carefully crafted escape sequences. This vulnerability specifically targets the Device Control Request Status String (DECRQSS) escape sequence functionality within xterm, where maliciously formatted text files can trigger command execution when processed by the terminal application. The flaw operates by exploiting the improper handling of line feed characters within the DECRQSS escape sequence, creating a pathway for command injection attacks that can be initiated through seemingly benign text files.
The technical implementation of this vulnerability stems from xterm's inadequate sanitization of escape sequences when processing Device Control Request Status String commands. When xterm encounters a DECRQSS escape sequence containing specially crafted line feed characters, it fails to properly validate or sanitize the input before executing any embedded commands. This processing error creates a direct injection vector where attacker-controlled content can be interpreted as executable commands rather than mere display formatting instructions. The vulnerability is particularly dangerous because it operates within the terminal's escape sequence processing logic, which is designed to handle device control commands and status queries, making it difficult to distinguish between legitimate and malicious sequences.
The operational impact of CVE-2008-2383 extends beyond simple command execution to encompass broader system compromise potential. Attackers can leverage this vulnerability to execute arbitrary code with the privileges of the user running xterm, potentially leading to complete system compromise if the terminal is used with elevated privileges. The vulnerability is particularly concerning in multi-user environments where users may inadvertently open malicious text files, or in scenarios where xterm is used in automated processes that process untrusted text content. This issue represents a significant escalation from previous similar vulnerabilities such as CVE-2003-0063 and CVE-2003-0071, which were also related to xterm's escape sequence handling but demonstrated more limited attack surface and impact.
Security mitigation strategies for CVE-2008-2383 should focus on both immediate patching and operational hardening measures. The primary solution involves updating xterm to versions that properly sanitize escape sequences and implement strict validation of Device Control Request Status String inputs. Organizations should also consider implementing content filtering mechanisms that can detect and block suspicious escape sequences in text files, particularly those that might be processed by terminal emulators. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1059.007 for command and script injection, and CWE-74 for improper neutralization of special elements in data flows. System administrators should also implement monitoring for unusual terminal activity and establish secure file handling practices that prevent untrusted text content from being processed by terminal applications without proper sanitization.
The broader implications of this vulnerability highlight the critical importance of proper input validation in terminal emulators and device control systems. This flaw demonstrates how escape sequence processing can become a vector for privilege escalation and arbitrary code execution when proper sanitization measures are absent. The vulnerability's relationship to CVE-2003-0063 and CVE-2003-0071 indicates a recurring pattern in xterm's escape sequence handling that requires comprehensive security review and remediation. Organizations should conduct thorough security assessments of their terminal emulator usage patterns and implement defensive measures such as restricting file permissions, using sandboxed terminal environments, and establishing security policies that govern the handling of untrusted text content in terminal processing contexts.