Security Resilience

CVE-2020-24363

Access Control in Tp-Link Tl-Wa855Re Firmware ≤ 200731

CISA KEVActive ExploitationEUVD ExploitedAccess Control
Published
31 August 2020
Modified
07 November 2025
KEV Added
02 September 2025
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.22 98th percentile
Risk Priority 90 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2020-24363 is a high-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Tp-Link Tl-Wa855Re Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique System Service Discovery (T1007); ranked in the top 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability tracked as CVE-2020-24363 affects TP-Link TL-WA855RE V5 devices running firmware version 20200415-rel37464. It stems from missing authentication for a critical function (CWE-306), allowing an unauthenticated actor on the local network to issue a TDDP_RESET POST request that forces a factory reset and reboot of the device.

An attacker positioned on the same network can exploit the flaw without credentials to reset the extender, after which they can configure a new administrative password and obtain full management access. The issue carries a CVSS 3.1 base score of 8.8 with an attack vector of adjacent network, low complexity, and no required privileges or user interaction.

Public references include a technical advisory and proof-of-concept material at malwrforensics.com along with TP-Link's firmware download page for the TL-WA855RE model; no additional mitigation details are supplied in the CVE record itself.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

TP-Link TL-WA855RE V5 20200415-rel37464 devices allow an unauthenticated attacker (on the same network) to submit a TDDP_RESET POST request for a factory reset and reboot. The attacker can then obtain incorrect access control by setting a new administrative password.

CWE(s)
KEV Date Added
02 September 2025

Related Threats

MITRE ATT&CK Enterprise Techniques

T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
T1027.004 Compile After Delivery Stealth
Adversaries may attempt to make payloads difficult to discover and analyze by delivering files to victims as uncompiled code.
T1027.006 HTML Smuggling Stealth
Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign HTML files.
T1027.007 Dynamic API Resolution Stealth
Adversaries may obfuscate then dynamically resolve API functions called by their malware in order to conceal malicious functionalities and impair defensive analysis.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-8627Same vendor: Tp-Link
CVE-2025-14300Same vendor: Tp-Link
CVE-2025-15517Same vendor: Tp-Link
CVE-2023-36851Shared CWE-306both on KEV
CVE-2024-11680Shared CWE-306both on KEV
CVE-2025-48572Shared CWE-306both on KEV
CVE-2025-0108Shared CWE-306both on KEV
CVE-2023-27532Shared CWE-306both on KEV
CVE-2021-35587Shared CWE-306both on KEV
CVE-2024-47575Shared CWE-306both on KEV

Affected Assets

tp-link
tl-wa855re firmware
≤ 200731

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 6 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V6.2.3
  • V6.4.4
  • V10.4.16
  • V12.1.3

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-306

Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.

addresses: CWE-306

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-306

Guarantees critical functions are protected by mandatory invocation of the access control mechanism.

addresses: CWE-306

Auditing sessions makes it possible to detect access to critical functions without required authentication.

addresses: CWE-306

The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.

addresses: CWE-306

Certification assesses that critical functions have required authentication controls in place.

addresses: CWE-306

Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-01 partial match
blocks

Managing identities and credentials is a prerequisite for authentication but does not itself enforce it on critical functions.

PR.AA-03 partial match
blocks

Directly requires authentication of users/services/hardware, which eliminates missing authentication for critical functions.

PR.AA-05 partial match
blocks

Defining and enforcing authorizations assumes prior authentication and therefore only partially mitigates the absence of authentication.

PR.IR-01 partial match
blocks

Protecting networks from unauthorized access can be undermined by missing authentication but does not address the root authentication gap.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

removes
removes
removes
blocks

Mandating authentication requirements for critical functions at the requirements-gathering stage ensures that essential operations are not left unprotected by missing login or verification mechanisms.

removes

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (higher-evidence rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248585 OL 8 must require reauthentication when using the "sudo" command. blocks CWE-306
  • V-248827 OL 8 must not have the rsh-server package installed. blocks CWE-306
RHEL 7 (2 rules)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. blocks CWE-306
  • V-237635 The Red Hat Enterprise Linux operating system must require re-authentication when using the "sudo" command. blocks CWE-306
RHEL 8 (2 rules)
  • V-230492 RHEL 8 must not have the rsh-server package installed. blocks CWE-306
  • V-237643 RHEL 8 must require re-authentication when using the "sudo" command. blocks CWE-306

References