CVE-2016-2181
No exploitation reported by the sources we read.
- Published2016-09-16
- WeaknessCWE-189
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
The Anti-Replay feature in the DTLS implementation in OpenSSL before 1.1.0 mishandles early use of a new epoch number in conjunction with a large sequence number, which allows remote attackers to cause a denial of service (false-positive packet drops) via spoofed DTLS records, related to rec_layer_d1.c and ssl3_record.c.
Timeline
dates in UTC- 2016-09-1605:59CVE publishedNVD
- 2026-10-2319:23EPSS crossed 10 %FIRST EPSS
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-2181?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-2181?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 1.0 | = 1.0.1 | no fix published | NVD |
| 1.0 | = 1.0.1a | no fix published | NVD |
| 1.0 | = 1.0.1b | no fix published | NVD |
| 1.0 | = 1.0.1c | no fix published | NVD |
| 1.0 | = 1.0.1d | no fix published | NVD |
| 1.0 | = 1.0.1e | no fix published | NVD |
| 1.0 | = 1.0.1f | no fix published | NVD |
| 1.0 | = 1.0.1g | no fix published | NVD |
| 1.0 | = 1.0.1h | no fix published | NVD |
| 1.0 | = 1.0.1i | no fix published | NVD |
| 1.0 | = 1.0.1j | no fix published | NVD |
| 1.0 | = 1.0.1k | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 6.x | = 6 | no fix published | NVD |
| 7.x | = 7 | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
Red Hat Security Advisory: openssl security update
Fix
- Vendor fix Red Hat Product Security RHSA-2016:1940 · 151 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 For the update to take effect, all services linked to the OpenSSL library must be restarted, or the system rebooted.
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.07.5read 2026-10-23
- NVDCVSS 2.05read 2026-10-23
- NVDweakness (CWE)CWE-189read 2026-10-23
- FIRST EPSSEPSS score22.6 %read 2026-10-23
Technical details
- CVSS v3 Vector
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2016-09-16
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2016-2181?
Is CVE-2016-2181 actively exploited?
What is the CVSS score for CVE-2016-2181?
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Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.