CVE-2016-6303

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 32.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2016-09-16 · updated 2026-06-17
Weakness: CWE-787

Description

Integer overflow in the MDC2_Update function in crypto/mdc2/mdc2dgst.c in OpenSSL before 1.1.0 allows remote attackers to cause a denial of service (out-of-bounds write and application crash) or possibly have unspecified other impact via unknown vectors.

Affected products

Node.js: before 0.12.16; from 4.0.0 before 4.6.0; from 6.0.0 before 6.6.0 — fixed in 0.12.16, 4.6.0, 6.6.0
OpenSSL: 1.0.1, 1.0.1a, 1.0.1b, 1.0.1c, 1.0.1d, 1.0.1e (+24)

How to fix

Upgrade to a fixed version: Node.js 0.12.16, 4.6.0, 6.6.0. Check the vendor advisory for mitigations.

References

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10759
http://www-01.ibm.com/support/docview.wss?uid=swg21995039
http://www.oracle.com/technetwork/security-advisory/cpuapr2018-3678067.html
http://www.oracle.com/technetwork/security-advisory/cpujan2018-3236628.html
http://www.oracle.com/technetwork/security-advisory/cpujul2017-3236622.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2016-2881722.html
http://www.oracle.com/technetwork/security-advisory/cpuoct2017-3236626.html
http://www.securityfocus.com/bid/92984
http://www.securitytracker.com/id/1036885
https://bto.bluecoat.com/security-advisory/sa132
https://bugzilla.redhat.com/show_bug.cgi?id=1370146
https://cert-portal.siemens.com/productcert/pdf/ssa-412672.pdf

Get alerted when CVE-2016-6303 or the next vulnerability affects your stack