CVE-2015-3890 in Open Litespeed
Summary
by MITRE
Use-after-free vulnerability in Open Litespeed before 1.3.10.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 01/13/2021
The CVE-2015-3890 vulnerability represents a critical use-after-free flaw in Open Litespeed web server software prior to version 1.3.10. This vulnerability occurs when the software improperly handles memory management during specific request processing scenarios, creating opportunities for remote code execution. The flaw manifests when the application processes certain HTTP requests that trigger memory deallocation followed by subsequent access to the freed memory region, allowing attackers to manipulate program execution flow through carefully crafted malicious input.
This vulnerability falls under the CWE-416 category, which specifically addresses use-after-free conditions in software systems. The technical implementation involves the web server's handling of dynamic memory allocation and deallocation during request processing, particularly when dealing with complex HTTP headers and request parameters. When an attacker crafts a request that causes the server to free memory associated with a data structure and then continues to reference that freed memory, the application becomes susceptible to arbitrary code execution. The vulnerability is particularly dangerous because it can be exploited remotely without authentication, making it a prime target for automated exploitation tools.
The operational impact of CVE-2015-3890 extends beyond simple privilege escalation or denial of service scenarios. Attackers can leverage this vulnerability to execute arbitrary code on the affected server with the privileges of the web server process, typically running as the 'www-data' user on Linux systems. This access can enable attackers to establish persistent backdoors, exfiltrate sensitive data, modify web content, or use the compromised server as a launch point for further attacks within the network infrastructure. The vulnerability affects any system running Open Litespeed version 1.3.9 or earlier, including various hosting environments and enterprise web applications that rely on this lightweight web server solution.
Security professionals should prioritize patching affected systems immediately, as this vulnerability has been actively exploited in the wild. The remediation process involves upgrading to Open Litespeed version 1.3.10 or later, which includes proper memory management fixes that prevent the use-after-free condition. Organizations should also implement network monitoring to detect exploitation attempts and consider deploying web application firewalls to block malicious requests. From an att&ck framework perspective, this vulnerability maps to techniques involving remote code execution and privilege escalation, with potential lateral movement opportunities once initial access is gained. Additionally, system administrators should conduct thorough security assessments of their web server configurations and implement proper input validation to minimize the attack surface and prevent similar vulnerabilities from emerging in other components of their infrastructure.