CVE-2015-6421
No exploitation reported by the sources we read.
- Published2016-01-27
- WeaknessCWE-399
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
cifs-ao in the CIFS optimization functionality on Cisco Wide Area Application Service (WAAS) and Virtual WAAS (vWAAS) devices 5.x before 5.3.5d and 5.4 and 5.5 before 5.5.3 allows remote attackers to cause a denial of service (resource consumption and device reload) via crafted network traffic, aka Bug ID CSCus85330.
Timeline
dates in UTC- 2016-01-2722:59CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2015-6421?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2015-6421?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 |
|---|---|---|---|
| 5.1 | = 5.1.1 | no fix published | NVD |
| 5.1 | = 5.1.1a | no fix published | NVD |
| 5.1 | = 5.1.1b | no fix published | NVD |
| 5.1 | = 5.1.1c | no fix published | NVD |
| 5.1 | = 5.1.1d | no fix published | NVD |
| 5.2 | = 5.2.1 | no fix published | NVD |
| 5.2 | = 5.2_base | no fix published | NVD |
| 5.3 | = 5.3.1 | no fix published | NVD |
| 5.3 | = 5.3.3 | no fix published | NVD |
| 5.3 | = 5.3.5 | no fix published | NVD |
| 5.3 | = 5.3.5a | no fix published | NVD |
| 5.3 | = 5.3.5b | no fix published | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- tools.cisco.comVendor Advisory
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 2.07.8read 2026-10-23
- NVDweakness (CWE)CWE-399read 2026-10-23
- FIRST EPSSEPSS score1.9 %2026-10-22
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
- 2016-01-27
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2015-6421?
Is CVE-2015-6421 actively exploited?
What is the CVSS score for CVE-2015-6421?
Hear about the next vulnerability in your software
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 ».
No credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.