CVE-2022-28049 in njs
Summary
by MITRE • 04/15/2022
NGINX NJS 0.7.2 was discovered to contain a NULL pointer dereference via the component njs_vmcode_array at /src/njs_vmcode.c.
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Analysis
by VulDB Data Team • 04/21/2022
The vulnerability identified as CVE-2022-28049 represents a critical NULL pointer dereference flaw within NGINX NJS version 0.7.2, specifically within the njs_vmcode_array component located at /src/njs_vmcode.c. This issue manifests as a potential crash condition that could be exploited to disrupt the normal operation of NGINX JavaScript engine implementations. The vulnerability arises from inadequate input validation and memory management within the JavaScript virtual machine code execution engine, where the system fails to properly handle null references during array processing operations.
The technical exploitation of this vulnerability occurs when the njs_vmcode_array function processes array operations without proper null pointer checks, leading to a situation where a NULL pointer is dereferenced during runtime execution. This type of flaw falls under CWE-476 which specifically addresses NULL Pointer Dereference conditions in software implementations. When an attacker can manipulate input data to trigger this condition, the JavaScript engine will attempt to access memory at a NULL address, causing an immediate application crash or potentially allowing for more sophisticated exploitation techniques depending on the execution environment.
The operational impact of CVE-2022-28049 extends beyond simple service disruption, as it represents a potential denial of service vulnerability that could be leveraged by malicious actors to destabilize web servers relying on NGINX JavaScript functionality. Systems utilizing NGINX with NJS modules for dynamic content generation, API handling, or server-side JavaScript processing become particularly vulnerable to this attack vector. The vulnerability could be exploited through crafted HTTP requests or JavaScript code execution that triggers the problematic array handling code path, potentially allowing for repeated service interruptions or system instability.
Mitigation strategies for this vulnerability primarily involve upgrading to a patched version of NGINX NJS where the NULL pointer dereference has been addressed through proper input validation and memory management procedures. Security administrators should prioritize patching affected systems and monitor for any exploitation attempts through network intrusion detection systems. Additionally, implementing proper input sanitization and validation measures within JavaScript code execution environments can help reduce the attack surface. The remediation approach aligns with ATT&CK technique T1499.004 which focuses on avoiding or mitigating denial of service attacks through proper software validation and error handling mechanisms. Organizations should also consider implementing runtime protections and monitoring solutions to detect anomalous behavior patterns that might indicate exploitation attempts targeting this specific vulnerability class.