Is CVE-2016-6886 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2016-6886 being exploited in the wild.

How severe is CVE-2016-6886?

High severity, with a CVSS score of 7.5, published 13 January 2017.

Which products and versions are affected?

MatrixSSL MatrixSSL before 3.8.4.

Is there a fix for CVE-2016-6886?

A patch was published on 2016-08-01: Fixed in MatrixSSL version 3.8.4 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2016-6886 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2016-6886?

Check whether you run Matrixssl. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2016-6886: MatrixSSL denial of service in pstm_reverse function

CVE-2016-6886 · Severity: high · CVSS 7.5 · Published 2017-01-13

MatrixSSL is a lightweight TLS/SSL library used to secure communications in embedded devices and applications. A vulnerability in how it handles certain cryptographic keys allows a remote attacker to crash the service by sending a specially crafted value during the initial connection handshake. This results in a denial of service, preventing legitimate users from establishing secure connections to the affected device or application.

Technologies: Matrixssl. Vendors: Matrixssl.

Quick answers

Is CVE-2016-6886 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2016-6886 being exploited in the wild.
How severe is CVE-2016-6886?: High severity, with a CVSS score of 7.5, published 13 January 2017.
Which products and versions are affected?: MatrixSSL MatrixSSL before 3.8.4.
Is there a fix for CVE-2016-6886?: A patch was published on 2016-08-01: Fixed in MatrixSSL version 3.8.4 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2016-6886 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2016-6886?: Check whether you run Matrixssl. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A denial of service vulnerability exists in the MatrixSSL bignum library within the pstm_reverse function. The function fails to properly handle zero-sized inputs, leading to an integer underflow of a length variable and a subsequent invalid memory read. This can be triggered remotely during an RSA key exchange if an attacker provides a zero value or a value equal to the key's modulus as the secret key. The resulting crash terminates the process. The issue was addressed in MatrixSSL version 3.8.4.

Affected products

MatrixSSL MatrixSSL before 3.8.4

Timeline

2016-07-31: disclosed: Initial public disclosure by Hanno Böck (The Fuzzing Project)
2016-08-01: patched: Fixed in MatrixSSL version 3.8.4
2017-01-13: advisory: NVD publication date

References

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