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Vulnerability record · CVE-2021-31624 · published 29 October 2021

CVE-2021-31624: Tendacn ac9 firmware classic buffer overflow vulnerability

Tendacn · Ac9 Firmware

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 urls parameter.

8.8 CVSS 3.1 High EPSS 1.1% · top 33.8% CWE-120 · Classic buffer overflow
8.8CVSS 3.1 base score, v2 5.8
1.1%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
9 Jul 2026Last modified by NVD

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 urls parameter.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/Lyc-heng/routers/blob/main/routers/stack2.md ExploitThird Party Advisory
https://github.com/Lyc-heng/routers/blob/main/routers/stack2.md ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-40942Tendacn ac9 firmware out-of-bounds write vulnerabilityTenda AC9 V3.0BR_V15.03.06.42_multi_TD01 was discovered stack overflow via parameter 'firewall_value' at url /goform/SetFirewallCfg.EPSS 0.84%9.8CVE-2020-22079Tendacn ac10u firmware out-of-bounds write vulnerabilityStack-based buffer overflow in Tenda AC-10U AC1200 Router US_AC10UV1.0RTL_V15.03.06.48_multi_TDE01 allows remote attackers to execute arbitrary code …EPSS 4.2%9.8CVE-2020-13389Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 2.6%9.8CVE-2020-13394Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 2.6%9.8CVE-2020-13392Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 2.6%9.8CVE-2020-13390Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 2.6%9.8CVE-2020-13393Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 3.3%9.8CVE-2020-13391Tendacn ac6 firmware classic buffer overflow vulnerabilityAn issue was discovered on Tenda AC6 V1.0 V15.03.05.19_multi_TD01, AC9 V1.0 V15.03.05.19(6318)_CN, AC9 V3.0 V15.03.06.42_multi, AC15 V1.0 V15.03.05.1…EPSS 2.6%

Source: NIST National Vulnerability Database (record CVE-2021-31624), CISA KEV, FIRST EPSS (scores of 2026-10-17). This page is refreshed as NVD updates the record.