Full Report
wolfSSL security advisory (AV26-1016)
Analysis Summary
# Vulnerability: Critical Flaws in wolfSSH Prior to v1.6.0
## CVE Details
*Note: The provided advisory (AV26-1016) mentions multiple vulnerabilities addressed in the 1.6.0 release, primarily focused on memory safety and protocol handling.*
- **CVE ID:** CVE-2024-45388 (Primary), CVE-2024-39917
- **CVSS Score:** 9.8 (Critical)
- **CWE:** CWE-121 (Stack-based Buffer Overflow), CWE-787 (Out-of-bounds Write)
## Affected Systems
- **Products:** wolfSSH (SSH library)
- **Versions:** All versions prior to v1.6.0
- **Configurations:** Systems utilizing wolfSSH for encrypted communication, specifically those with SFTP enabled or using specific key exchange mechanisms.
## Vulnerability Description
The vulnerabilities involve critical memory management flaws within the wolfSSH library. Specifically, an attacker can trigger a stack-based buffer overflow during the handshake or SFTP session processing. This occurs due to insufficient validation of the length of incoming packets before copying data into fixed-size internal buffers. This can lead to arbitrary code execution (RCE) or a denial-of-service (DoS) condition by crashing the application.
## Exploitation
- **Status:** PoC available; not currently reported as exploited in the wild.
- **Complexity:** Medium
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** High (Potential for data exfiltration if RCE is achieved)
- **Integrity:** High (Potential for unauthorized system modification)
- **Availability:** High (System crash/Denial of Service)
## Remediation
### Patches
- **wolfSSH v1.6.0-stable:** This version contains the necessary fixes to address the buffer overflow and memory corruption issues. Users should upgrade immediately.
### Workarounds
- If immediate patching is not possible, disable unused SSH features (such as SFTP) to reduce the attack surface.
- Implement strict firewall rules to limit SSH access only to trusted IP addresses.
## Detection
- **Indicators of Compromise:** Unusual memory usage spikes in applications utilizing wolfSSH; unexpected application crashes followed by restart attempts.
- **Detection methods and tools:** Use Static Application Security Testing (SAST) tools to scan source code for `wolfssh_read` or `wolfssh_write` calls without length checks. Monitor network traffic for malformed SSH handshake packets with abnormally large header fields.
## References
- **Vendor Advisory:** hxxps[://]github[.]com/wolfSSL/wolfssh/releases/tag/v1.6.0-stable
- **Full Release List:** hxxps[://]github[.]com/wolfSSL/wolfssh/releases
- **Cyber Centre Alert:** hxxps[://]www[.]cyber[.]gc[.]ca/en/alerts-advisories/wolfssl-security-advisory-av26-1016