CVE-2010-0002 in bash
Summary
by MITRE
The /etc/profile.d/60alias.sh script in the Mandriva bash package for Bash 2.05b, 3.0, 3.2, 3.2.48, and 4.0 enables the --show-control-chars option in LS_OPTIONS, which allows local users to send escape sequences to terminal emulators, or hide the existence of a file, via a crafted filename.
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Analysis
by VulDB Data Team • 11/18/2024
The vulnerability described in CVE-2010-0002 resides within the bash package distribution by Mandriva, specifically targeting the /etc/profile.d/60alias.sh script that is executed during shell initialization. This flaw affects multiple versions of bash including 2.05b, 3.0, 3.2, 3.2.48, and 4.0, creating a persistent security risk across a wide range of systems that utilize these bash versions. The vulnerability stems from the improper handling of the LS_OPTIONS environment variable, which is configured to include the --show-control-chars option, a configuration that inadvertently exposes systems to terminal escape sequence injection attacks.
The technical flaw manifests through the manipulation of the LS_OPTIONS variable within the bash profile script, where the --show-control-chars option is enabled by default. This configuration change allows local attackers to craft filenames that contain escape sequences which get interpreted by terminal emulators when the ls command is executed. When a user lists directory contents containing such maliciously crafted filenames, the terminal emulator processes these escape sequences, potentially executing unintended commands or altering the display behavior of the terminal. The vulnerability operates at the intersection of shell environment configuration and terminal rendering, creating a vector for both information disclosure and potential command injection through carefully constructed file names that contain control characters.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to manipulate terminal sessions and potentially hide file existence from casual observation. Local users can exploit this weakness to create filenames that either send escape sequences to terminal emulators, causing unexpected behavior or even command execution in vulnerable terminal implementations, or to obscure the presence of files in directory listings. This dual nature makes the vulnerability particularly dangerous as it can be used for both reconnaissance and active exploitation. The attack requires local system access but can be leveraged to create persistent backdoors or to obscure malicious activities within system directories, making it a significant concern for system administrators who must maintain visibility into system file structures.
Mitigation strategies for CVE-2010-0002 should focus on disabling the problematic LS_OPTIONS configuration that enables --show-control-chars option, which can be accomplished by modifying or removing the /etc/profile.d/60alias.sh script or by overriding the LS_OPTIONS variable in user shell configurations. System administrators should also implement proper file naming conventions and regular monitoring of directory listings for suspicious filenames that might contain control characters. The vulnerability aligns with CWE-157 weakness category related to improper handling of control characters and can be mapped to ATT&CK technique T1059.007 for command and script injection. Organizations should also consider implementing automated scanning tools to detect potentially malicious filenames and ensure that all bash installations are updated to versions that do not contain this vulnerable configuration. The remediation process requires careful consideration of existing system configurations to avoid breaking legitimate functionality while addressing the security exposure.