CVE-2000-0618 in xconq
Summary
by MITRE
Buffer overflow in xconq and cconq game programs on Red Hat Linux allows local users to gain additional privileges via long DISPLAY environmental variable.
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Analysis
by VulDB Data Team • 06/25/2021
The vulnerability described in CVE-2000-0618 represents a critical buffer overflow condition affecting the xconq and cconq game programs distributed with Red Hat Linux systems. This flaw resides in the handling of the DISPLAY environment variable, which is commonly used by X Window System applications to specify the display server they should connect to. The buffer overflow occurs when the programs process an excessively long DISPLAY variable, causing memory corruption that can be exploited by local attackers to escalate privileges. The vulnerability specifically impacts systems running Red Hat Linux and demonstrates the inherent risks associated with improper input validation in system utilities that handle user-supplied environment variables.
The technical implementation of this buffer overflow stems from inadequate bounds checking within the xconq and cconq applications when processing the DISPLAY environment variable. When a local user sets an overly long DISPLAY value, the programs fail to properly validate the input length before copying it into fixed-size buffers allocated in memory. This classic buffer overflow scenario allows an attacker to overwrite adjacent memory locations, potentially including return addresses or other critical program state information. The vulnerability is particularly dangerous because it requires no network access and can be exploited through local user accounts, making it a significant concern for system administrators who must consider privilege escalation risks in their security posture.
The operational impact of CVE-2000-0618 extends beyond simple privilege escalation to encompass broader system compromise potential. Local users who exploit this vulnerability can gain elevated privileges, potentially allowing them to execute arbitrary code with higher permissions than their original account. This could enable attackers to modify system files, install backdoors, access sensitive data, or disable security mechanisms. The vulnerability affects the core functionality of these gaming applications but also illustrates how seemingly benign environment variable handling can create security weaknesses that attackers can leverage for more serious attacks. Systems running these programs become vulnerable to local privilege escalation attacks, which can be particularly concerning in multi-user environments or shared computing resources.
Mitigation strategies for this vulnerability should focus on immediate patching of affected systems and implementation of environment variable validation controls. System administrators must update their Red Hat Linux installations to include security patches that address the buffer overflow conditions in xconq and cconq. Additionally, implementing proper input validation for environment variables and establishing monitoring for suspicious DISPLAY variable usage can help detect potential exploitation attempts. The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and demonstrates the importance of following secure coding practices that prevent memory corruption vulnerabilities. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and represents a common vector for local attackers seeking to gain elevated system access through application-level flaws. Organizations should also consider implementing least privilege principles and regular security assessments to identify similar vulnerabilities in other system components that may be susceptible to similar buffer overflow exploitation patterns.