CyberSecBulletin
CVE-2024-51138NVD status: Modified

Vigor3912 Firmware: Stack-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2024-51138 is a critical-severity stack-based buffer overflow vulnerability in Vigor3912 Firmware from DrayTek, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 4.4.3.2 as the first without the flaw, so updating Vigor3912 Firmware to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.05% chance of exploitation within 30 days, higher than 65% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Vigor3912 Firmware to 4.4.3.2 or a later version.
  2. Update Vigor2620 Firmware to 3.9.9.1 or a later version.
  3. Update Vigorlte200 Firmware to 3.9.9.1 or a later version.
  4. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
DraytekVigor3912 Firmwarebefore 4.4.3.24.4.3.2
DraytekVigor2620 Firmwarebefore 3.9.9.13.9.9.1
DraytekVigorlte200 Firmwarebefore 3.9.9.13.9.9.1
DraytekVigor2860 Firmwarebefore 3.9.8.33.9.8.3
DraytekVigor2925 Firmwarebefore 3.9.8.33.9.8.3
DraytekVigor2862 Firmwarebefore 3.9.9.83.9.9.8
DraytekVigor2926 Firmwarebefore 3.9.9.83.9.9.8
DraytekVigor2133 Firmwarebefore 3.9.9.23.9.9.2
DraytekVigor2762 Firmwarebefore 3.9.9.23.9.9.2
DraytekVigor2832 Firmwarebefore 3.9.9.23.9.9.2
DraytekVigor2135 Firmwarebefore 4.4.5.54.4.5.5
DraytekVigor2765 Firmwarebefore 4.4.5.54.4.5.5
DraytekVigor2766 Firmwarebefore 4.4.5.54.4.5.5
DraytekVigor2763 Firmwarebefore 4.4.5.54.4.5.5
DraytekVigor2865 Firmwarebefore 4.4.5.84.4.5.8
DraytekVigor2866 Firmwarebefore 4.4.5.84.4.5.8
DraytekVigor2927 Firmwarebefore 4.4.5.84.4.5.8
DraytekVigor2962 Firmwarebefore 4.3.2.9; 4.4.3 up to, but not including, 4.4.3.24.3.2.9, 4.4.3.2
DraytekVigor3910 Firmwarebefore 4.3.2.9; 4.4.3 up to, but not including, 4.4.3.24.3.2.9, 4.4.3.2
DraytekVigor2915 Firmwarebefore 4.4.54.4.5
DraytekVigor1000b Firmwarebefore 4.4.3.24.4.3.2
DraytekVigor2952 Firmwarebefore 3.9.8.53.9.8.5
DraytekVigor3220 Firmwarebefore 3.9.8.53.9.8.5

Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).

Official description

Vigor165/166 4.2.7 and earlier; Vigor2620/LTE200 3.9.8.9 and earlier; Vigor2860/2925 3.9.8 and earlier; Vigor2862/2926 3.9.9.5 and earlier; Vigor2133/2762/2832 3.9.9 and earlier; Vigor2135/2765/2766 4.4.5. and earlier; Vigor2865/2866/2927 4.4.5.3 and earlier; Vigor2962 4.3.2.8 and earlier; Vigor3912 4.3.6.1 and earlier; Vigor3910 4.4.3.1 and earlier a stack-based buffer overflow vulnerability has been identified in the URL parsing functionality of the TR069 STUN server. This flaw occurs due to insufficient bounds checking on the amount of URL parameters, allowing an attacker to exploit the overflow by sending a maliciously crafted request. Consequently, a remote attacker can execute arbitrary code with elevated privileges.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Stack-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the stack.

How developers prevent this class of flaw

  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Implement and perform bounds checking on input.

More Stack-based Buffer Overflow vulnerabilities (CWE-121)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Vigor3912 Firmware

All Vigor3912 Firmware vulnerabilities

Recent Stack-based Buffer Overflow vulnerabilities

Spotted an error? Tell us.