CVE-2024-51139

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-27 · updated 2026-07-05
Weakness: CWE-120

Description

Buffer Overflow vulnerability in Vigor2620/LTE200 3.9.8.9 and earlier and Vigor2860/2925 3.9.8 and earlier and Vigor2862/2926 3.9.9.5 and earlier and Vigor2133/2762/2832 3.9.9 and earlier and Vigor165/166 4.2.7 and earlier and Vigor2135/2765/2766 4.4.5.1 and earlier and Vigor2865/2866/2927 4.4.5.3 and earlier and Vigor2962/3910 4.3.2.8/4.4.3.1 and earlier and Vigor3912 4.3.6.1 and earlier allows a remote attacker to execute arbitrary code via the CGI parser's handling of the "Content-Length" header of HTTP POST requests.

Affected products

DrayTek Vigor1000B Firmware: before 4.4.3.2 — fixed in 4.4.3.2
DrayTek Vigor2133 Firmware: before 3.9.9.2 — fixed in 3.9.9.2
DrayTek Vigor2135 Firmware: before 4.4.5.5 — fixed in 4.4.5.5
DrayTek Vigor2620 Firmware: before 3.9.9.1 — fixed in 3.9.9.1
DrayTek Vigor2762 Firmware: before 3.9.9.2 — fixed in 3.9.9.2
DrayTek Vigor2763 Firmware: before 4.4.5.5 — fixed in 4.4.5.5
DrayTek Vigor2765 Firmware: before 4.4.5.5 — fixed in 4.4.5.5
DrayTek Vigor2766 Firmware: before 4.4.5.5 — fixed in 4.4.5.5
DrayTek Vigor2832 Firmware: before 3.9.9.2 — fixed in 3.9.9.2
DrayTek Vigor2860 Firmware: before 3.9.8.3 — fixed in 3.9.8.3
DrayTek Vigor2862 Firmware: before 3.9.9.8 — fixed in 3.9.9.8
DrayTek Vigor2865 Firmware: before 4.4.5.8 — fixed in 4.4.5.8
DrayTek Vigor2866 Firmware: before 4.4.5.8 — fixed in 4.4.5.8
DrayTek Vigor2915 Firmware: before 4.4.5 — fixed in 4.4.5
DrayTek Vigor2925 Firmware: before 3.9.8.3 — fixed in 3.9.8.3
DrayTek Vigor2926 Firmware: before 3.9.9.8 — fixed in 3.9.9.8
DrayTek Vigor2927 Firmware: before 4.4.5.8 — fixed in 4.4.5.8
DrayTek Vigor2952 Firmware: before 3.9.8.5 — fixed in 3.9.8.5
DrayTek Vigor2962 Firmware: before 4.3.2.9; from 4.4.3 before 4.4.3.2 — fixed in 4.3.2.9, 4.4.3.2
DrayTek Vigor3220 Firmware: before 3.9.8.5 — fixed in 3.9.8.5
DrayTek Vigor3910 Firmware: before 4.3.2.9; from 4.4.3 before 4.4.3.2 — fixed in 4.3.2.9, 4.4.3.2
DrayTek Vigor3912 Firmware: before 4.4.3.2 — fixed in 4.4.3.2
DrayTek Vigorlte200 Firmware: before 3.9.9.1 — fixed in 3.9.9.1

How to fix

Upgrade to a fixed version: DrayTek Vigor1000B Firmware 4.4.3.2; DrayTek Vigor2133 Firmware 3.9.9.2; DrayTek Vigor2135 Firmware 4.4.5.5; DrayTek Vigor2620 Firmware 3.9.9.1; DrayTek Vigor2762 Firmware 3.9.9.2; DrayTek Vigor2763 Firmware 4.4.5.5; DrayTek Vigor2765 Firmware 4.4.5.5; DrayTek Vigor2766 Firmware 4.4.5.5; DrayTek Vigor2832 Firmware 3.9.9.2; DrayTek Vigor2860 Firmware 3.9.8.3; DrayTek Vigor2862 Firmware 3.9.9.8; DrayTek Vigor2865 Firmware 4.4.5.8. Check the vendor advisory for mitigations.

References

https://medium.com/faraday/advisory-multiple-vulnerabilities-affecting-draytek-routers-78a6cb8b3946

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