CVE-2016-7055

What it is

There is a carry propagating bug in the Broadwell-specific Montgomery multiplication procedure in OpenSSL 1.0.2 and 1.1.0 before 1.1.0c that handles input lengths divisible by, but longer than 256 bits. Analysis suggests that attacks against RSA, DSA and DH private keys are impossible. This is because the subroutine in question is not used in operations with the private key itself and an input of the attacker's direct choice. Otherwise the bug can manifest itself as transient authentication and key negotiation failures or reproducible erroneous outcome of public-key operations with specially crafted input. Among EC algorithms only Brainpool P-512 curves are affected and one presumably can attack ECDH key negotiation. Impact was not analyzed in detail, because pre-requisites for attack are considered unlikely. Namely multiple clients have to choose the curve in question and the server has to share the private key among them, neither of which is default behaviour. Even then only clients that chose the curve will be affected.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of service disruption.

Exploit odds

14.2% chance of exploitation in the next 30 days (EPSS). Higher than most.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2017-05-04 20:29 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 00:52 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 14.2% in the next 30 days (EPSS).
• Severity: 5.9 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2017-05-04 20:29 UTC

Last modified

2026-06-17 00:52 UTC

Exploit probability

14.2% · EPSS, next 30 days

Record status

Modified

Affected

• OpenSSL < 1.0.2k
• OpenSSL < 1.1.0c
• Nodejs node.js ≤ 4.1.2
• Nodejs node.js < 4.7.3
• Nodejs node.js ≤ 6.8.1
• Nodejs node.js < 6.9.5
• Nodejs node.js < 7.5.0

Attack profile CVSS 3.1 · 5.9

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2016-7055.md and follow it. Check whether this project is affected by CVE-2016-7055. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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