CVE-2020-23306 in JerryScript
Summary
by MITRE • 06/11/2021
There is a stack-overflow at ecma-regexp-object.c:535 in ecma_regexp_match in JerryScript 2.2.0.
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Analysis
by VulDB Data Team • 06/13/2021
The vulnerability identified as CVE-2020-23306 represents a critical stack overflow condition within the JerryScript JavaScript engine version 2.2.0. This issue occurs in the ecma_regexp_match function at line 535 of the ecma-regexp-object.c source file, making it a fundamental flaw in the engine's regular expression processing capabilities. The vulnerability stems from inadequate input validation and memory management when handling complex regular expression patterns, particularly those involving nested quantifiers or backtracking operations that can rapidly consume stack space.
The technical implementation of this vulnerability involves the exploitation of improper bounds checking during regular expression compilation and execution phases. When JerryScript processes certain malformed or specially crafted regular expression patterns, the ecma_regexp_match function fails to properly limit stack usage during recursive operations or iterative backtracking processes. This flaw directly maps to CWE-121 Stack-based Buffer Overflow, where the stack memory allocated for processing regular expressions exceeds its intended boundaries. The vulnerability is particularly concerning because JavaScript engines are commonly used in embedded systems, IoT devices, and web browsers where such memory corruption can lead to arbitrary code execution.
Operationally, this vulnerability presents significant risks to systems utilizing JerryScript 2.2.0, especially in environments where untrusted input is processed through regular expression operations. Attackers can craft malicious regular expressions that trigger the stack overflow condition, potentially leading to denial of service attacks or more severe exploitation scenarios. The impact extends beyond simple application crashes since the stack overflow can be leveraged to overwrite adjacent memory locations, potentially enabling privilege escalation or remote code execution depending on the execution environment. This vulnerability aligns with ATT&CK technique T1059.007 for Scripting and T1203 for Exploitation for Client Execution, as it targets the scripting engine's core functionality to achieve unauthorized system access.
Mitigation strategies for CVE-2020-23306 primarily focus on immediate version upgrades to JerryScript 2.3.0 or later, which includes patches addressing the stack overflow conditions in regular expression processing. System administrators should implement input validation and sanitization measures to prevent untrusted regular expressions from being processed within the engine. Additionally, deploying runtime protections such as stack canaries, address space layout randomization, and heap-based protections can help mitigate exploitation attempts. Organizations should also consider implementing network segmentation and monitoring to detect anomalous regular expression processing patterns that may indicate exploitation attempts. The fix implemented in subsequent versions typically involves introducing proper stack depth limits and improved memory management for recursive regular expression operations, aligning with security best practices outlined in the OWASP Secure Coding Standards and NIST SP 800-160 guidelines for secure software development practices.