attack-surface.md

Attack Surface Analysis for phpdocumentor/reflectioncommon

Attack Surface: Regular Expression Denial of Service (ReDoS)

• Description: reflection-common might use poorly designed regular expressions for parsing PHP code structures. An attacker could craft specific input strings that cause these regexes to take an excessively long time to process due to backtracking, leading to Denial of Service. This vulnerability directly resides within the library's parsing logic.
• Reflection-common Contribution: Parsing code structures inherently involves regular expressions for tokenization and pattern matching. Vulnerable regexes within reflection-common's code are the direct source of this attack surface.
• Example: An attacker crafts a complex namespace string specifically designed to exploit a vulnerable regular expression within reflection-common. When the application uses the library to parse this string, the regex engine enters a catastrophic backtracking scenario, consuming excessive CPU time and causing a DoS. The application becomes unresponsive due to the library's internal processing bottleneck.
• Impact: Denial of Service (DoS), potentially rendering the application unusable.
• Risk Severity: High (If vulnerable regexes exist in commonly used parsing paths within the library and are reachable through application functionality).
• Mitigation Strategies:
  • Regex Review and Optimization (Library Level): The primary mitigation is for the reflection-common maintainers to rigorously review and optimize all regular expressions within the library's codebase. Regexes should be designed to avoid backtracking vulnerabilities. Consider using regex analysis tools to detect potential ReDoS issues.
  • Timeouts (Application Level - Defensive): As a defensive measure in the application using the library, implement timeouts for parsing operations that utilize reflection-common. If parsing takes longer than an acceptable threshold, terminate the operation to prevent prolonged resource consumption. This is a workaround, not a fix for the underlying regex issue in the library.
  • Report Vulnerabilities: If you identify potential ReDoS vulnerabilities in reflection-common's regexes, report them to the library maintainers immediately so they can be addressed in future releases.

Attack Surface: Indirect Code Execution (Through Application Logic Exploiting Parsing Weaknesses - Potentially Critical)

• Description: While reflection-common is not designed for code execution itself, weaknesses in its parsing logic, combined with insecure application-level usage of the parsed data, could indirectly create a path to code execution. This is a more complex scenario but needs consideration if the application heavily relies on reflection data for critical operations.
• Reflection-common Contribution: If reflection-common's parsing is flawed and can be manipulated to produce unexpected or attacker-controlled reflection data (e.g., crafted namespace or class names that bypass validation within the library), this manipulated data can then be exploited by vulnerable application logic. The flaw in parsing within reflection-common is the contributing factor here.
• Example: Imagine reflection-common has a parsing vulnerability that allows an attacker to inject special characters or escape sequences into a parsed namespace name. If the application then uses this parsed namespace name in a dynamic class loading operation without proper further sanitization, an attacker might be able to craft an input that, after being processed by reflection-common and then used by the application, leads to loading and executing a malicious class. This is a chain of vulnerabilities, but starts with a parsing weakness in reflection-common.
• Impact: Code Execution, potentially leading to full system compromise. This is a critical impact if successfully exploited.
• Risk Severity: Potentially Critical (If a parsing vulnerability in reflection-common can be chained with insecure application logic to achieve code execution. This requires both a flaw in the library and vulnerable application code).
• Mitigation Strategies:
  • Secure Parsing Logic (Library Level): The primary mitigation is for reflection-common to have robust and secure parsing logic that prevents manipulation of parsed data through crafted inputs. Thorough input validation and sanitization within the library itself are crucial.
  • Secure Application Logic (Application Level): Even with a secure reflection-common, applications must never trust reflection data derived from potentially untrusted sources (like user input) without rigorous validation and sanitization at the application level. Avoid dynamic code execution based on reflection data if possible. If necessary, use strict whitelists and validation.
  • Security Audits and Penetration Testing: Conduct thorough security audits of both reflection-common (report findings to maintainers) and applications using it. Penetration testing should specifically target scenarios where manipulated inputs are processed by reflection-common and then used in application logic to identify potential code execution paths.