CVE-2008-4101 in Vim
Summary
by MITRE
Vim 3.0 through 7.x before 7.2.010 does not properly escape characters, which allows user-assisted attackers to (1) execute arbitrary shell commands by entering a K keystroke on a line that contains a ";" (semicolon) followed by a command, or execute arbitrary Ex commands by entering an argument after a (2) "Ctrl-]" (control close-square-bracket) or (3) "g]" (g close-square-bracket) keystroke sequence, a different issue than CVE-2008-2712.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/04/2025
This vulnerability affects vim text editors version 3.0 through 7.x before 7.2.010 and represents a critical command injection flaw that stems from improper character escaping mechanisms. The vulnerability manifests when users interact with specific keyboard sequences that trigger command execution without proper sanitization of input data. The flaw allows attackers to escalate privileges and execute arbitrary shell commands or Ex commands through seemingly innocuous user interactions, making it particularly dangerous in multi-user environments or when vim is used with elevated privileges. This vulnerability is classified as a command injection issue under CWE-77 and falls under the broader category of improper input validation.
The technical implementation of this vulnerability occurs through three distinct attack vectors that exploit different keyboard input handling mechanisms within the vim editor. The first vector involves pressing the K keystroke on lines containing semicolon characters followed by commands, which bypasses normal input sanitization and executes the command directly in the shell. The second and third vectors utilize control key combinations Ctrl-] and g] respectively, where attackers can append arguments to trigger arbitrary Ex command execution. These keyboard sequences are processed without proper escaping of special characters, allowing attackers to inject malicious commands that are then interpreted by the underlying shell or vim command processor. The vulnerability exists because vim fails to properly sanitize user input when these specific keystroke combinations are processed, creating an execution path that directly translates user input into system commands.
The operational impact of this vulnerability extends beyond simple command execution to encompass potential privilege escalation and system compromise scenarios. When vim is executed with elevated privileges or in environments where users have write access to files that may be processed by vim, attackers can leverage this vulnerability to gain unauthorized access to system resources, execute malicious code, and potentially establish persistent access. The user-assisted nature of this vulnerability means that exploitation requires some form of user interaction, but this interaction can be achieved through social engineering or by tricking users into opening malicious files. The vulnerability affects a wide range of vim versions and is particularly concerning because vim is widely installed across Unix-like systems and is often used with root privileges, amplifying the potential impact of successful exploitation.
Mitigation strategies for this vulnerability include immediate patching to version 7.2.010 or later where the character escaping issues have been resolved. System administrators should also implement strict input validation policies and consider restricting vim usage in privileged contexts where possible. Security monitoring should focus on detecting unusual vim usage patterns, particularly when users interact with files containing special characters or when vim is used in conjunction with elevated privileges. Organizations should also consider implementing privilege separation techniques and restricting write access to files that may be processed by vim to reduce the attack surface. This vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter and T1548.001 for abuse of privileges, highlighting the need for comprehensive security controls that address both the immediate vulnerability and broader privilege management concerns. Regular security assessments should include verification of vim installations and their configuration to ensure that proper escaping mechanisms are in place and functioning correctly.