CVE-2021-3382 in Gitea
Summary
by MITRE • 02/05/2021
Stack buffer overflow vulnerability in gitea 1.9.0 through 1.13.1 allows remote attackers to cause a denial of service (crash) via vectors related to a file path.
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Analysis
by VulDB Data Team • 02/24/2021
The vulnerability identified as CVE-2021-3382 represents a critical stack buffer overflow flaw affecting Gitea versions 1.9.0 through 1.13.1. This issue stems from improper input validation when processing file paths within the application's codebase, creating a scenario where remote attackers can exploit the weakness to cause system instability. The vulnerability manifests when the application receives malformed or excessively long file path inputs that exceed the allocated stack buffer space, leading to memory corruption that ultimately results in application crashes. The attack vector specifically targets the file path handling mechanisms, making it particularly dangerous in environments where Gitea processes user-uploaded content or handles external file references. This type of vulnerability falls under the Common Weakness Enumeration category CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The operational impact of this vulnerability extends beyond simple denial of service, as it can potentially be leveraged by attackers to execute arbitrary code or escalate privileges, depending on the system configuration and memory layout. The vulnerability's remote exploitability means that attackers do not require local system access to trigger the condition, making it a significant concern for publicly accessible Gitea instances. Organizations utilizing affected Gitea versions face substantial risk of service disruption and potential security compromise, particularly in environments where the application serves as a central code repository management system.
The technical exploitation of CVE-2021-3382 occurs when an attacker crafts a malicious file path input that exceeds the predetermined stack buffer limits within Gitea's file handling routines. This overflow can overwrite return addresses, function pointers, and other critical memory segments, causing the application to crash or behave unpredictably. The vulnerability's exploitation typically involves sending specially crafted HTTP requests containing extended file path parameters that trigger the buffer overflow during processing. Attackers may also leverage this weakness in conjunction with other techniques to achieve more sophisticated attacks, such as information disclosure or privilege escalation. The specific implementation flaw lies in the application's failure to properly validate the length of file path inputs before copying them into fixed-size stack buffers. This weakness aligns with ATT&CK technique T1203, which describes the exploitation of software vulnerabilities to gain unauthorized access or execute malicious code. The vulnerability's impact is amplified by the fact that Gitea is commonly deployed in environments where it handles sensitive code repositories, making the potential consequences of exploitation particularly severe. Security researchers have noted that the vulnerability's exploitation can be automated, allowing for mass deployment of denial of service attacks against multiple Gitea instances simultaneously.
Organizations affected by CVE-2021-3382 must implement immediate mitigations to protect their systems from potential exploitation. The most effective solution involves upgrading to Gitea version 1.13.2 or later, which contains the necessary patches to address the buffer overflow condition. System administrators should also consider implementing input validation measures at network boundaries to filter out suspicious file path parameters before they reach the application. Additional protective measures include deploying intrusion detection systems that can identify patterns associated with buffer overflow exploitation attempts, and implementing application-level monitoring to detect unusual memory usage patterns that may indicate exploitation activity. The vulnerability's characteristics make it particularly suitable for exploitation through automated scanning tools, as demonstrated by various security research organizations that have documented successful exploitation against vulnerable systems. Organizations should also conduct thorough security assessments of their Gitea deployments to identify any additional configurations or customizations that might exacerbate the vulnerability's impact. Furthermore, implementing proper logging and monitoring capabilities will help detect exploitation attempts and provide valuable forensic data for incident response activities. The remediation process should include not only patching the affected software but also reviewing the application's overall security posture and ensuring that similar buffer overflow vulnerabilities are addressed throughout the codebase. Organizations may also benefit from implementing network segmentation strategies to limit the potential impact of successful exploitation attempts, particularly in environments where multiple services share the same infrastructure.