CVE-2016-10931

An issue was discovered in the openssl crate before 0.9.0 for Rust. There is an SSL/TLS man-in-the-middle vulnerability because certificate verification is off by default and there is no API for hostname verification.

Published: 2019-08-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2016-10931 is rated Moderate Risk (50.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.74%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2016-10931

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.18% 0.74% +0.56%
2 2025-03-30 0.43% 0.18% -0.25%
3 2025-03-29 — 0.43% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2016-10931

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.0 HIGH
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.2 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2016-10931

GitHub Security Advisory for CVE-2016-10931

GHSA-34p9-f4q3-c4r7 · Severity: high · Ecosystem: rust — Improper Certificate Validation in openssl

OS Trackers for CVE-2016-10931

vendor priority summary link
debian unimportant CVE-2016-10931 unimportant priority: Debian including 1 source packages (rust-openssl), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2016-10931
ubuntu medium CVE-2016-10931 medium priority: Ubuntu including 1 source packages (rust-openssl), 6 status rows across 6 suites (bionic, disco, eoan, trusty, upstream, xenial): DNE 3, not-affected 2, ignored 1. https://ubuntu.com/security/CVE-2016-10931

Affected software / configurations for CVE-2016-10931

Vendor Product Version Raw CPE
rust-openssl_project rust-openssl < 0.9.0 cpe:2.3:a:rust-openssl_project:rust-openssl:*:*:*:*:*:*:*:*

References for CVE-2016-10931

URL Tags
https://rustsec.org/advisories/RUSTSEC-2016-0001.html Release Notes Vendor Advisory
cvelogic Threat Intelligence