CVE-2021-27246

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of TP-Link Archer A7 AC1750 1.0.15 routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of MAC addresses by the tdpServer endpoint. A crafted TCP message can write stack pointers to the stack. An attacker can leverage this vulnerability to execute code in the context of the root user. Was ZDI-CAN-12306.

Published: 2021-04-14 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-27246 is rated Moderate Risk (59.5/100): CVSS High severity, with high exploitation likelihood (EPSS 6.60%, 93th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize 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-2021-27246

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 15.92% 6.60% -9.33%
2 2026-05-23 12.38% 15.92% +3.55%
3 2026-05-02 — 12.38% —

Full EPSS history (24 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-27246

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.0 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 2.1 5.9 [email protected]
8.0 3.0 HIGH
CVSS:3.0/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
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.
 2.1 5.9 [email protected]
7.9 2.0 HIGH
AV:A/AC:M/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:A)
Requires access to an adjacent network segment.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 5.5 10.0 [email protected]

Weakness enumeration for CVE-2021-27246

Affected software / configurations for CVE-2021-27246

Vendor Product Version Raw CPE
tp-link ac1750_firmware 1.0.15 cpe:2.3:o:tp-link:ac1750_firmware:1.0.15:*:*:*:*:*:*:*

References for CVE-2021-27246

URL Tags
https://www.zerodayinitiative.com/advisories/ZDI-21-215/ Third Party Advisory VDB Entry
cvelogic Threat Intelligence