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CVE-2016-6884 Matrixssl CVE debrief

CVE-2016-6884 is a denial-of-service vulnerability in MatrixSSL affecting CBC-mode cipher suites used in TLS 1.1 and TLS 1.2. According to NVD, a crafted message can trigger an out-of-bounds read, which may crash the affected service. The vulnerable range is MatrixSSL versions through 3.8.2; the vendor changelog reference and NVD description indicate the issue is addressed in 3.8.3 and later.

Vendor
Matrixssl
Product
CVE-2016-6884
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2017-03-03
Original CVE updated
2026-05-13
Advisory published
2017-03-03
Advisory updated
2026-05-13

Who should care

Teams that ship or operate applications, appliances, or embedded systems using MatrixSSL for TLS termination should review this issue, especially if CBC-mode cipher suites are enabled for TLS 1.1 or TLS 1.2. Operators concerned with service availability are the primary audience because the reported impact is denial of service rather than confidentiality or integrity loss.

Technical summary

NVD identifies the weakness as CWE-125 (out-of-bounds read). The CVSS vector is AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H, which reflects a remotely reachable issue that can be triggered with user interaction and can seriously impact availability. The affected CPE range in NVD ends at MatrixSSL 3.8.2.

Defensive priority

Medium. The issue is network-reachable and can disrupt service availability, but it does not indicate direct data theft or code execution in the supplied record. Prioritize remediation if MatrixSSL is exposed to untrusted network traffic or if CBC cipher suites remain enabled.

Recommended defensive actions

  • Upgrade MatrixSSL to version 3.8.3 or later, as indicated by the NVD description and the vendor changelog reference.
  • Confirm whether your deployments use TLS 1.1 or TLS 1.2 CBC-mode cipher suites and disable unnecessary CBC suites where operationally feasible.
  • Inventory products and firmware that bundle MatrixSSL, since the affected library may be embedded in appliances or third-party software.
  • Validate availability monitoring and crash-recovery procedures for any externally reachable TLS services using MatrixSSL.
  • Track the linked vendor changelog and NVD record for any additional remediation guidance or version confirmation.

Evidence notes

The debrief is based on the NVD record for CVE-2016-6884, which lists MatrixSSL versions through 3.8.2 as vulnerable and classifies the weakness as CWE-125. The NVD references include an oss-security mailing list post dated 2016-08-19, a SecurityFocus BID entry, and the MatrixSSL CHANGES.md file. No exploit details beyond the supplied description are used.

Official resources

The CVE record was published on 2017-03-03, and the NVD record was last modified on 2026-05-13. The NVD references also point to an oss-security advisory dated 2016-08-19, which provides earlier disclosure context.