Attack Surface: Buffer Overflow in Response Parsing
Description: Hiredis might not properly validate the size of incoming Redis responses, especially string lengths or array sizes, leading to buffer overflows when parsing. Hiredis Contribution: Hiredis is responsible for parsing the raw byte stream received from the Redis server. Insufficient bounds checking within hiredis's parsing logic is the direct cause of this vulnerability. Example: A malicious Redis server or a man-in-the-middle attacker sends a crafted response with an extremely long string length. Hiredis attempts to allocate or write to a buffer based on this length without proper validation, causing a write beyond the buffer's boundaries. Impact: Memory corruption, application crash, denial of service, potentially arbitrary code execution. Risk Severity: High Mitigation Strategies:
- Use the latest version of hiredis to benefit from potential security patches.
- Employ memory safety tools like AddressSanitizer (ASan) or Valgrind during development and testing to detect buffer overflows.
- Restrict network access to the Redis server to trusted sources to minimize the risk of malicious responses.
Attack Surface: Integer Overflow/Underflow in Length Handling
Description: Hiredis uses integers to represent lengths of strings and arrays in Redis responses. Integer overflows or underflows during length calculations can lead to incorrect memory allocation or processing, potentially resulting in buffer overflows. Hiredis Contribution: Hiredis's parsing logic relies on integer arithmetic to handle lengths provided in Redis responses. Lack of proper checks for overflow/underflow conditions in these calculations within hiredis is the direct vulnerability. Example: A crafted Redis response includes an extremely large length value for a string or array. When hiredis performs calculations with this length, an integer overflow occurs, leading to a smaller-than-expected buffer allocation. Subsequent operations might then write beyond this undersized buffer. Impact: Memory corruption, application crash, denial of service, unexpected program behavior. Risk Severity: High Mitigation Strategies:
- Use the latest version of hiredis to leverage potential fixes for integer handling vulnerabilities.
- Review hiredis release notes for mentions of integer overflow/underflow related fixes.
- Consider server-side validation to prevent excessively large or negative length values in responses (if server-side control is possible).
Attack Surface: Double Free or Use-After-Free
Description: Memory corruption vulnerabilities arising from double-freeing the same memory block or using memory after it has been freed. Hiredis Contribution: Bugs in hiredis's internal memory management logic, specifically within connection handling, error conditions, or asynchronous operations within hiredis, can directly lead to these memory corruption issues. Example: A specific sequence of Redis commands and responses, or error conditions during connection handling, triggers a double free or use-after-free vulnerability within hiredis's memory management routines. Impact: Memory corruption, application crash, denial of service, potentially arbitrary code execution. Risk Severity: High Mitigation Strategies:
- Use the latest version of hiredis, as these types of vulnerabilities are critical and often patched quickly.
- Utilize memory safety tools like ASan or Valgrind during development to detect double-free and use-after-free errors.
- Focus testing efforts on error handling paths and edge cases to uncover potential memory management issues within hiredis interactions.
- Report any suspected double-free or use-after-free vulnerabilities to the hiredis developers with detailed reproduction steps.
Attack Surface: TLS/SSL Vulnerabilities (if TLS is enabled)
Description: If TLS/SSL is enabled for secure communication, vulnerabilities in the TLS library used by hiredis (or in hiredis's TLS integration itself) can be exploited. Hiredis Contribution: Hiredis integrates with TLS libraries (like OpenSSL) to provide encrypted communication. Vulnerabilities in these underlying libraries or in hiredis's TLS integration and configuration are directly relevant to hiredis's attack surface when TLS is used. Example: Exploiting a known vulnerability in OpenSSL (if used by hiredis) or weaknesses in hiredis's TLS configuration to perform man-in-the-middle attacks, decrypt communication, or cause denial of service. Impact: Confidentiality breach (data interception), data integrity compromise, denial of service. Risk Severity: High Mitigation Strategies:
- Keep hiredis and the underlying TLS library (e.g., OpenSSL) updated to the latest versions to patch known vulnerabilities.
- Ensure proper TLS configuration with strong ciphers and certificate validation.
- Regularly update TLS libraries as part of a security maintenance process.
- Evaluate and consider using alternative TLS implementations if supported by hiredis and deemed more secure or actively maintained.