CVE-2020-26304 in foundation-sites
Summary
by MITRE • 10/26/2024
Foundation is a front-end framework. Versions 6.3.3 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, it is unknown if any fixes are available.
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Analysis
by VulDB Data Team • 11/14/2024
The vulnerability identified as CVE-2020-26304 affects the Foundation front-end framework, specifically versions 6.3.3 and earlier, presenting a critical security risk through Regular Expression Denial of Service (ReDoS) vulnerabilities. This issue resides within the framework's regular expression implementations that process user input, creating opportunities for malicious actors to exploit the system's computational resources through carefully crafted input sequences. The vulnerability stems from poorly constructed regular expressions that exhibit exponential backtracking behavior when processing certain input patterns, leading to significant performance degradation or complete service unavailability.
The technical flaw manifests when the Foundation framework processes user-provided data through vulnerable regular expressions that contain nested quantifiers with overlapping patterns. These patterns cause the regular expression engine to perform an exponential number of operations, effectively consuming CPU resources and preventing the application from processing legitimate requests. The vulnerability operates at the input validation layer where the framework parses and sanitizes user input, making it particularly dangerous as it can be triggered through various interaction points including form submissions, API endpoints, or any user-facing input field. The exponential backtracking behavior creates a resource exhaustion scenario where a single malicious input can cause the system to hang or crash, directly impacting availability and potentially leading to denial of service conditions for legitimate users.
The operational impact of this vulnerability extends beyond simple service disruption, as it represents a fundamental weakness in the framework's input handling capabilities that could be exploited in distributed denial of service attacks or to consume excessive computational resources in cloud environments. Attackers can craft specific input patterns that trigger the vulnerable regular expressions, causing the application servers to become unresponsive and potentially leading to cascading failures in larger systems that depend on Foundation components. The vulnerability affects the framework's core functionality and can compromise the overall security posture of applications built using Foundation, particularly in environments where resource constraints are critical such as shared hosting or containerized deployments.
Security practitioners should prioritize immediate mitigation efforts including upgrading to Foundation versions 6.3.4 or later where patches are available, implementing input validation and sanitization measures at the application level, and monitoring for suspicious input patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-400, which classifies regular expression denial of service as a weakness in input validation, and represents a common attack pattern categorized under the ATT&CK framework's resource exhaustion techniques. Organizations should also consider implementing rate limiting and input length restrictions as defensive measures while awaiting official patches, and conduct thorough testing of their applications to identify other potential vulnerable regular expressions within their codebase. The incident underscores the importance of regular security assessments and staying current with framework updates to prevent exploitation of known vulnerabilities.