CVE-2024-27282 in Ruby
Summary
by MITRE • 05/14/2024
An issue was discovered in Ruby 3.x through 3.3.0. If attacker-supplied data is provided to the Ruby regex compiler, it is possible to extract arbitrary heap data relative to the start of the text, including pointers and sensitive strings. The fixed versions are 3.0.7, 3.1.5, 3.2.4, and 3.3.1.
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Analysis
by VulDB Data Team • 05/11/2026
This vulnerability represents a critical heap data exposure issue in Ruby's regular expression engine that affects versions 3.0.0 through 3.3.0. The flaw occurs when the regex compiler processes attacker-controlled input, creating a condition where memory contents can be inadvertently exposed through the compilation process. This type of vulnerability falls under the category of information disclosure through memory corruption patterns and aligns with CWE-200, which addresses improper exposure of sensitive information. The vulnerability is particularly concerning because it allows attackers to extract arbitrary heap data that may contain pointers, sensitive strings, and other confidential information that could be leveraged for further exploitation.
The technical implementation of this vulnerability stems from how Ruby's regex engine handles memory allocation and pointer arithmetic during pattern compilation. When processing attacker-supplied regex patterns, the compiler may not properly validate bounds checking or memory access patterns, leading to situations where the compiled regex structure can reference memory locations outside the intended text buffer. This memory leakage occurs at the heap level and can expose data that was previously stored in memory segments adjacent to the regex processing area. The vulnerability demonstrates a classic buffer overread condition that can be exploited through careful crafting of regex patterns to access memory regions that should remain private.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially enable more sophisticated attacks. An attacker who can successfully exploit this vulnerability gains access to heap memory contents that may include sensitive data such as cryptographic keys, user credentials, session tokens, or other confidential information stored in adjacent memory locations. This capability aligns with ATT&CK technique T1005, which covers data from local system, and can serve as a stepping stone for additional attacks including privilege escalation or credential theft. The vulnerability is particularly dangerous in applications that process untrusted input through regex operations, such as web applications, log parsing systems, or any system that accepts user-supplied patterns for matching operations.
Mitigation strategies for this vulnerability require immediate patching to the fixed versions 3.0.7, 3.1.5, 3.2.4, and 3.3.1, which contain the necessary fixes to prevent the heap data exposure. Organizations should prioritize updating their Ruby installations across all affected systems and validate that the patches have been properly applied. Additionally, implementing input validation and sanitization measures can help reduce the attack surface by limiting the amount of untrusted data that reaches the regex processing layer. Security monitoring should include detection of unusual regex pattern characteristics that might indicate exploitation attempts, and network segmentation can help limit the potential impact if exploitation occurs. The vulnerability also highlights the importance of regular security assessments and keeping all runtime dependencies up to date, as similar memory safety issues can exist in other components of the application stack.