CVE-2021-3328 in Abyss Web Server
Summary
by MITRE • 04/09/2021
An issue was discovered in Aprelium Abyss Web Server X1 2.12.1 and 2.14. A crafted HTTP request can lead to an out-of-bounds read that crashes the application.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 04/15/2021
The vulnerability identified as CVE-2021-3328 resides within the Aprelium Abyss Web Server X1 versions 2.12.1 and 2.14, representing a critical out-of-bounds read condition that fundamentally compromises the application's memory integrity. This flaw manifests when the web server processes specifically crafted HTTP requests, triggering a memory access violation that results in application crash. The vulnerability stems from inadequate input validation mechanisms within the HTTP request parsing logic, where the server fails to properly bounds-check data structures when handling malformed or unexpected request parameters. Such memory corruption issues fall under the Common Weakness Enumeration category CWE-125, which specifically addresses out-of-bounds read vulnerabilities that occur when a program accesses memory beyond the boundaries of a buffer or array. The attack surface for this vulnerability is significant as it directly impacts the web server's ability to process incoming HTTP traffic, potentially enabling denial of service conditions that can disrupt legitimate service availability.
The operational impact of CVE-2021-3328 extends beyond simple application instability, as it creates opportunities for adversaries to exploit the memory corruption for more sophisticated attacks. When the web server crashes due to the out-of-bounds read, it creates a window of opportunity for attackers to either maintain persistent denial of service conditions or potentially leverage the instability for information disclosure. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous in environments where the web server handles critical business operations or serves as a gateway to internal systems. From an adversarial perspective, this vulnerability aligns with the MITRE ATT&CK framework's technique T1499.004, which involves network denial of service attacks that specifically target web applications. The crash condition can be triggered through various HTTP request methods and headers, making it difficult to implement effective network-based detection mechanisms that rely on specific request patterns or signatures.
Mitigation strategies for CVE-2021-3328 should prioritize immediate patch application from the vendor, as this represents the most effective defense against the vulnerability. Organizations should also implement network-level protections such as intrusion detection systems that monitor for unusual HTTP request patterns and automated web application firewalls that can detect and block malformed requests before they reach the vulnerable server. Additionally, defensive measures including input validation at multiple layers, application sandboxing, and regular memory integrity checks can help reduce the overall risk exposure. The vulnerability's nature as an out-of-bounds read also emphasizes the importance of implementing robust memory safety practices such as address space layout randomization, stack canaries, and compiler-based buffer overflow protections. System administrators should also conduct regular vulnerability assessments to identify similar patterns in other web server implementations and ensure that all third-party applications undergo thorough security testing before deployment. The incident underscores the critical need for maintaining up-to-date security patches and implementing comprehensive security monitoring procedures that can quickly detect and respond to exploitation attempts targeting memory corruption vulnerabilities.