CVE-2021-40633 is a high-severity vulnerability found in giflib version 5.1.4, identified as a memory leak that may lead to out-of-memory exceptions or denial of service when processed with maliciously crafted GIF files. This vulnerability is particularly concerning as it can be exploited remotely, posing significant risks to organizations that rely on this library for handling GIF image formats.
The CVSS score for this vulnerability is 8.8, indicating a high severity level, which necessitates immediate attention from security teams. The attack vector is network-based, suggesting that no physical access is required to exploit the vulnerability. Given the potential for denial of service, organizations utilizing giflib should prioritize patching operations.
Risk to organizations includes significant downtime and service disruption, which can affect user trust and operational continuity. Organizations are advised to assess their exposure to this vulnerability and implement remediation strategies without delay.
As of now, there are no known exploits in the wild, and no public proof of concept has been confirmed. However, the combination of high severity and the potential for exploitation underscores the importance of taking proactive measures.
Vulnerability Details
The vulnerability identified as CVE-2021-40633 is a memory leak (out-of-memory) in the gif2rgb utility within giflib 5.1.4. It allows remote attackers to trigger an out-of-memory exception or denial of service via specially crafted GIF files. This flaw is classified under CWE-401: Memory Leak.
The vulnerability was published on June 14, 2022, and affects the giflib component developed by giflib_project. The CVSS 3.1 vector string for this vulnerability is CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H, indicating high impacts on confidentiality, integrity, and availability.
Technical Analysis
The root cause of CVE-2021-40633 is a failure in the gif2rgb utility to properly manage memory allocations, leading to a scenario where excessive memory consumption can occur. The attack vector is network-based, allowing an attacker to send a crafted GIF file to the vulnerable application without requiring any prior access or authentication.
The attack complexity is classified as low, meaning that an attacker can exploit this vulnerability without needing advanced skills. However, user interaction is required, as the victim must open the crafted GIF file for exploitation to occur.
In terms of impact, this vulnerability affects confidentiality, integrity, and availability, with all three metrics rated as high. This indicates that successful exploitation can lead to unauthorized access to sensitive data, manipulation of data, and a complete denial of service.
Risk & Impact Analysis
The real-world deployment risk associated with CVE-2021-40633 is substantial, particularly for organizations that utilize giflib in applications exposed to the internet. The potential for denial of service could lead to significant operational disruptions, affecting both revenue and reputation.
Given the high CVSS score, organizations should assess their exposure to this vulnerability and prioritize patching in their security management processes. The blast radius could extend to any application utilizing the vulnerable version of giflib, impacting users and services reliant on those applications.
Urgency for patching is critical, as attackers may leverage this vulnerability to cause significant disruptions. Organizations should implement patches immediately to mitigate potential risks.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The only affected version identified is giflib 5.1.4. Organizations using this version should apply the necessary patches to mitigate the vulnerability. If version information is missing, organizations should assume all versions prior to vendor patch are at risk.
Mitigation & Remediation
Organizations should prioritize patching giflib to the latest version released by giflib_project. For those unable to immediately patch, consider applying workarounds such as disabling GIF processing or implementing network controls to filter malicious file uploads. Additionally, monitoring for unusual memory usage patterns can help detect potential exploitation attempts.
For further guidance on penetration testing and security validation, organizations can explore penetration testing services to assess their security posture.
Detection Guidance
To detect potential exploitation of CVE-2021-40633, organizations should monitor logs for indicators of out-of-memory exceptions and unusual application behavior. Behavioral anomalies or spikes in memory usage when processing GIF files may signal attempts to exploit this vulnerability. Implementing network signatures that identify malicious GIF uploads can also enhance detection capabilities.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2021-40633 highlights the importance of secure memory management in applications handling user-uploaded content. This vulnerability represents a common pattern in software development where inadequate resource management can lead to severe consequences for system stability.
Security teams should take lessons from this incident and implement stricter coding standards, thorough testing, and regular security audits to catch similar vulnerabilities early in the development lifecycle. To further enhance their security posture, organizations can refer to the following resources:
penetration testing methodology, vulnerability management program design, and API penetration testing guide for comprehensive insights.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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