CVE-2018-1000021 in Git
Summary
by MITRE
GIT version 2.15.1 and earlier contains a Input Validation Error vulnerability in Client that can result in problems including messing up terminal configuration to RCE. This attack appear to be exploitable via The user must interact with a malicious git server, (or have their traffic modified in a MITM attack).
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Analysis
by VulDB Data Team • 10/24/2024
The vulnerability identified as CVE-2018-1000021 represents a critical input validation error within Git client software versions 2.15.1 and earlier. This flaw exists in the client-side processing of git protocol data and can be exploited through malicious interactions with git servers or man-in-the-middle attacks that modify network traffic. The vulnerability stems from insufficient validation of input received during git protocol operations, creating potential attack vectors that can compromise terminal configurations and potentially enable remote code execution.
The technical implementation of this vulnerability involves the Git client's failure to properly validate and sanitize input received from remote servers during protocol operations. When users interact with malicious git servers or encounter modified traffic in MITM scenarios, the client processes unvalidated data that can manipulate terminal settings and command execution contexts. This input validation failure allows attackers to inject malicious commands or manipulate the client environment in ways that can escalate privileges and potentially achieve full system compromise. The vulnerability specifically affects the client-side git protocol handling mechanisms that process server responses and data streams during repository operations.
The operational impact of CVE-2018-1000021 extends beyond simple data corruption to encompass serious security implications including terminal configuration manipulation and potential remote code execution capabilities. An attacker exploiting this vulnerability can disrupt normal terminal operations, potentially leading to credential exposure or system compromise. The requirement for user interaction with malicious servers or MITM conditions means that organizations must consider both network security controls and user awareness training as part of their defense strategy. This vulnerability affects the fundamental trust model of git operations and can undermine secure development practices that rely on git as a core collaboration tool.
Organizations should implement immediate mitigation strategies including updating to Git versions 2.15.2 or later where this vulnerability has been addressed. Network security controls should be strengthened to detect and prevent MITM attacks, including implementing proper certificate validation and monitoring for suspicious git protocol traffic. The vulnerability aligns with CWE-20 Input Validation and CWE-74 Improper Neutralization of Special Elements in Output Used by a Downstream Component, and maps to ATT&CK techniques including T1059 Command and Scripting Interpreter and T1068 Exploitation for Privilege Escalation. Security teams should conduct comprehensive vulnerability assessments of their git infrastructure and implement network segmentation to limit exposure to potentially malicious git servers. Regular security updates and patch management processes should be enforced to prevent exploitation of similar input validation flaws in development tools and protocols.