CVE-2022-0741 in Community Edition
Summary
by MITRE • 04/02/2022
Improper input validation in all versions of GitLab CE/EE using sendmail to send emails allowed an attacker to steal environment variables via specially crafted email addresses.
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Analysis
by VulDB Data Team • 04/05/2022
The vulnerability identified as CVE-2022-0741 represents a critical security flaw in GitLab Community Edition and Enterprise Edition versions that utilize sendmail for email functionality. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied email addresses before processing them through the sendmail command. The flaw specifically manifests when GitLab attempts to send emails to addresses containing specially crafted malicious input that can exploit command injection vulnerabilities in the underlying sendmail implementation.
The technical exploitation of this vulnerability occurs through the manipulation of email address formats that contain shell metacharacters or special sequences. When GitLab processes these malformed addresses, the system passes the unvalidated input directly to the sendmail command without proper sanitization, creating an environment where attackers can inject arbitrary shell commands. This type of vulnerability falls under the CWE-77 category, specifically CWE-77: Improper Neutralization of Special Elements used in a Command, which is a well-documented weakness in command execution contexts. The vulnerability is particularly dangerous because it allows attackers to access sensitive environment variables that may contain database credentials, API keys, or other confidential information stored within the GitLab server's execution context.
The operational impact of CVE-2022-0741 extends beyond simple command injection, as it provides attackers with potential access to the underlying system's environment variables and configuration data. This access can lead to unauthorized data extraction, privilege escalation, and further compromise of the GitLab instance. The vulnerability affects all versions of GitLab CE/EE that rely on sendmail for email delivery, making it a widespread concern for organizations using these platforms. Attackers can leverage this flaw to execute arbitrary commands with the privileges of the GitLab service account, potentially leading to complete system compromise.
Organizations should immediately implement mitigations including updating to patched versions of GitLab where available, configuring alternative email delivery methods that do not rely on sendmail, or implementing strict input validation for email addresses. The ATT&CK framework categorizes this vulnerability under T1059.001 - Command and Scripting Interpreter: PowerShell, though the specific technique involves command injection through email processing rather than PowerShell specifically. System administrators should also consider implementing network segmentation, monitoring for suspicious email address patterns, and regular security assessments to identify potential exploitation attempts. Additionally, organizations should review their email configuration settings to ensure that sendmail is not being used in environments where untrusted input may be processed, as this vulnerability demonstrates how seemingly benign functionality can become a critical attack vector when proper input validation is absent.