CVE-2021-31627: tendacn ac9_firmware Classic Buffer Overflow
CVSS: 8.8v3.1HighModified
Published 29-10-2021Last modified 09-07-2026
Vulnerability summary
CVE-2021-31627 is a high (CVSS 8.8) Classic Buffer Overflow vulnerability in tendacn ac9_firmware. EPSS estimates a 1.14% chance of exploitation in the next 30 days, higher than 66.4% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
8.8/10
010
High · v3.1 (NVD)EPSS score
1.14%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 29-10-2021PublishedVulnerability first disclosed.
- 09-07-2026Last modifiedVulnerability information updated.
Description
Buffer Overflow vulnerability in Tenda AC9 V1.0 through V15.03.05.19(6318), and AC9 V3.0 V15.03.06.42_multi, allows attackers to execute arbitrary code via the index parameter.
CVSS metrics
2 scores · 1 source · 2 versionsHigh 8.8Preferred score · NVD (NIST)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesSingle source
Medium 5.8Preferred score · NVD (NIST)
AV:A/AC:L/Au:N/C:P/I:P/A:PSourcesSingle source
EPSS trend
Probability
1.14%
Chance of exploitation in the next 30 days
Percentile
66%
Versus all other CVEs
30-day change
0.00 pp
From 1.14% on 22-09-2026
22-09-202622-10-2026
EPSS score1.14%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundRouters
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Tendacn1 product
- ac9_firmware≤ 15.03.06.42_multi | ≤ 15.03.05.19\(6318\)
1 vendor · 1 product