CVE-2022-28738 in JD Edwards EnterpriseOne Tools
Summary
by MITRE • 05/09/2022
A double free was found in the Regexp compiler in Ruby 3.x before 3.0.4 and 3.1.x before 3.1.2. If a victim attempts to create a Regexp from untrusted user input, an attacker may be able to write to unexpected memory locations.
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Analysis
by VulDB Data Team • 05/09/2026
The vulnerability identified as CVE-2022-28738 represents a critical double free error within Ruby's regular expression compiler component affecting versions prior to 3.0.4 and 3.1.2. This flaw exists in the Regexp compiler implementation where improper memory management occurs during the processing of malicious regular expression patterns. The vulnerability stems from insufficient validation and handling of user-supplied input when constructing regular expression objects, creating opportunities for memory corruption that can be exploited by malicious actors.
The technical nature of this vulnerability places it squarely within the realm of memory safety issues classified under CWE-415, which specifically addresses double free conditions in software implementations. When Ruby processes a specially crafted regular expression pattern from untrusted input, the compiler's memory management routines execute the same free operation twice on the same memory block, leading to unpredictable behavior and potential exploitation. This memory corruption occurs during the compilation phase of regular expressions, where the parser fails to properly track allocated memory resources and their subsequent deallocation sequences.
The operational impact of this vulnerability extends beyond simple memory corruption, as it can potentially enable remote code execution or denial of service conditions when applications process untrusted regular expression input. Attackers can craft malicious regular expression patterns that, when processed by Ruby's Regexp compiler, trigger the double free condition. This allows for arbitrary memory writes to unexpected locations, potentially enabling attackers to overwrite critical program structures, function pointers, or other memory regions. The vulnerability is particularly dangerous in web applications where user input is commonly processed through regular expressions for validation, filtering, or parsing purposes.
Applications utilizing Ruby versions affected by CVE-2022-28738 are at significant risk when processing untrusted user input through regular expression operations. The attack surface includes any application that accepts user-supplied patterns for regular expression compilation, including web applications, API endpoints, or any system component that performs pattern matching operations on external data. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, as it can be leveraged to execute arbitrary code through memory corruption attacks, and T1211 for Exploitation for Defense Evasion, where attackers might use the vulnerability to bypass security controls.
Mitigation strategies for this vulnerability primarily involve upgrading to Ruby versions 3.0.4 or 3.1.2 and later, which contain the necessary patches to address the double free condition in the Regexp compiler. Organizations should prioritize immediate deployment of these security updates across all affected systems and applications. Additionally, implementing proper input validation and sanitization measures can provide defense-in-depth protection, ensuring that user-supplied regular expression patterns are properly validated before processing. The vulnerability also highlights the importance of regular security assessments and maintaining up-to-date software dependencies to prevent exploitation of known memory safety issues. Organizations should conduct comprehensive testing to verify that the patched versions maintain application functionality while eliminating the risk of memory corruption through regular expression processing.