Cyber Resilience

CVE-2024-41334

Crypto Weakness in Draytek Vigor166 Firmware ≤ 4.2.6

Published
27 February 2025
Modified
05 July 2026
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0037 30th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2024-41334 is a high-severity Improper Certificate Validation (CWE-295) vulnerability in Draytek Vigor166 Firmware. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Adversary-in-the-Middle (T1557); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-17 (Public Key Infrastructure Certificates) and SC-23 (Session Authenticity) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

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

CVE-2024-41334 is an improper certificate validation vulnerability (CWE-295) affecting multiple Draytek Vigor router models, including Vigor 165/166 prior to v4.2.6, Vigor 2620/LTE200 prior to v3.9.8.8, Vigor 2860/2925 prior to v3.9.7, Vigor 2862/2926 prior to v3.9.9.4, Vigor 2133/2762/2832 prior to v3.9.8, Vigor 2135/2765/2766 prior to v4.4.5.1, Vigor 2865/2866/2927 prior to v4.4.5.3, Vigor 2962/3910 prior to v4.3.2.7, Vigor 3912 prior to v4.3.5.2, and Vigor 2925 up to v3.9.6. The flaw occurs because these devices do not perform certificate verification when uploading APPE (Application Program Extension Environment) modules, enabling the installation of modules from unauthorized sources.

Attackers can exploit this vulnerability over the network with low complexity and low privileges (PR:L), requiring no user interaction. Successful exploitation allows uploading crafted APPE modules from non-official servers, resulting in arbitrary code execution on the device. The CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects high impacts on confidentiality, integrity, and availability.

Mitigation involves updating affected devices to the vendor-recommended firmware versions listed above, as indicated in the vulnerability description. Additional details are available in advisories from Draytek at http://draytek.com and Faraday Labs at https://medium.com/faraday/advisory-multiple-vulnerabilities-affecting-draytek-routers-78a6cb8b3946.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Draytek devices Vigor 165/166 prior to v4.2.6 , Vigor 2620/LTE200 prior to v3.9.8.8, Vigor 2860/2925 prior to v3.9.7, Vigor 2862/2926 prior to v3.9.9.4, Vigor 2133/2762/2832 prior to v3.9.8, Vigor 2135/2765/2766 prior to v4.4.5.1, Vigor 2865/2866/2927 prior to v4.4.5.3, Vigor 2962/3910…

more

prior to v4.3.2.7, Vigor 3912 prior to v4.3.5.2, and Vigor 2925 up to v3.9.6 were discovered to not utilize certificate verification, allowing attackers to upload crafted APPE modules from non-official servers, leading to arbitrary code execution.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1557 Adversary-in-the-Middle Credential Access
Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as [Network Sniffing](https://attack.
T1557.002 ARP Cache Poisoning Credential Access
Adversaries may poison Address Resolution Protocol (ARP) caches to position themselves between the communication of two or more networked devices.
T1557.003 DHCP Spoofing Credential Access
Adversaries may redirect network traffic to adversary-owned systems by spoofing Dynamic Host Configuration Protocol (DHCP) traffic and acting as a malicious DHCP server on the victim network.
T1557.004 Evil Twin Credential Access
Adversaries may host seemingly genuine Wi-Fi access points to deceive users into connecting to malicious networks as a way of supporting follow-on behaviors such as [Network Sniffing](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-41339Same product: Draytek Vigor165
CVE-2024-41338Same product: Draytek Vigor165
CVE-2024-41340Same product: Draytek Vigor165
CVE-2024-41594Same product: Draytek Vigor165
CVE-2024-41592Same product: Draytek Vigor165
CVE-2024-41588Same product: Draytek Vigor165
CVE-2024-41596Same product: Draytek Vigor165
CVE-2024-41593Same product: Draytek Vigor165
CVE-2024-41587Same product: Draytek Vigor165
CVE-2024-41590Same product: Draytek Vigor165

Affected Assets

draytek
vigor166 firmware
≤ 4.2.6
draytek
vigor2620 firmware
≤ 3.9.8.8
draytek
vigorlte200 firmware
≤ 3.9.8.8
draytek
vigor2860 firmware
≤ 3.9.7
draytek
vigor2925 firmware
≤ 3.9.7
draytek
vigor2862 firmware
≤ 3.9.9.4
draytek
vigor2926 firmware
≤ 3.9.9.4
draytek
vigor2133 firmware
≤ 3.9.8
draytek
vigor2762 firmware
≤ 3.9.8
draytek
vigor2832 firmware
≤ 3.9.8
+10 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 12 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

PKI certificate issuance and acquisition under an approved policy establishes the trusted roots and processes needed for correct validation.

Protecting session authenticity depends on cryptographic mechanisms whose trust depends on correct certificate validation.

Requiring confidentiality and integrity protection of transmitted data drives use of properly validated certificates in protocols such as TLS.

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-03 mostly match
prevents

Certificate-based authentication of users/services/hardware directly depends on correct validation.

PR.DS-02 mostly match
prevents

Proper certificate validation is a core mechanism for protecting data-in-transit confidentiality and integrity.

PR.PS-06 mostly match
prevents

Secure development practices explicitly include implementing correct certificate validation logic.

ID.RA-09 partial match
prevents

Assessing authenticity/integrity of acquired software often relies on code-signing certificate validation.

PR.AA-04 partial match
prevents

Identity assertions conveyed via certificates require validation to be verified.

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.

prevents

Requiring issuance and validation of public-key certificates under an approved policy reduces the chance that certificates with improper validation will be trusted.

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` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (3 rules)
  • V-248574 YUM must be configured to prevent the installation of patches, service packs, device drivers, or OL 8 system components that have not been digitally signed using a certificate that is recognized and approved by the organization. prevents CWE-295
  • V-248531 OL 8, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. prevents CWE-295
  • V-248575 OL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 7 (2 rules)
  • V-204447 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-204448 The Red Hat Enterprise Linux operating system must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
RHEL 8 (2 rules)
  • V-230264 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components from a repository without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295
  • V-230265 RHEL 8 must prevent the installation of software, patches, service packs, device drivers, or operating system components of local packages without verification they have been digitally signed using a certificate that is issued by a Certificate Authority (CA) that is recognized and approved by the organization. prevents CWE-295

References