CyberSecBulletin
CVE-2023-33778NVD status: Modified

Myvigor: Use of Hard-coded Credentials

Published Updated By the CyberSecBulletin desk

CVE-2023-33778 is a critical-severity use of hard-coded credentials vulnerability in Myvigor 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 2.3.2 as the first without the flaw, so updating Myvigor to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Myvigor to 2.3.2 or a later version.
  2. Update Vigorswitch Pq2200xb Firmware to 2.6.7 or a later version.
  3. Update Vigorswitch Pq2121x Firmware to 2.6.7 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
DraytekMyvigorbefore 2.3.22.3.2
DraytekVigorswitch Pq2200xb Firmwarebefore 2.6.72.6.7
DraytekVigorswitch Pq2121x Firmwarebefore 2.6.72.6.7
DraytekVigorswitch P2540xs Firmwarebefore 2.6.72.6.7
DraytekVigorswitch P2280x Firmwarebefore 2.6.72.6.7
DraytekVigorswitch P2100 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch Q2200x Firmwarebefore 2.6.72.6.7
DraytekVigorswitch Q2121x Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G2540xs Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G2280x Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G2121 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G2100 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch Fx2120 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch P1282 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G1282 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G1085 Firmwarebefore 2.6.72.6.7
DraytekVigorswitch G1080 Firmwarebefore 2.6.72.6.7
DraytekVigorap 903 Firmwarebefore 1.4.01.4.0
DraytekVigorap 912c Firmwarebefore 1.4.01.4.0
DraytekVigorap 918r Firmwarebefore 1.4.01.4.0
DraytekVigorap 1060c Firmwarebefore 1.4.01.4.0
DraytekVigorap 906 Firmwarebefore 1.4.01.4.0
DraytekVigorap 960c Firmwarebefore 1.4.01.4.0
DraytekVigorap 1000c Firmwarebefore 1.4.01.4.0
DraytekVigor2766ac Firmwarebefore 3.9.6; 4.0.0 up to, but not including, 4.2.43.9.6, 4.2.4

Version data comes from NVD's product matching; 35 further products are omitted here. 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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)

Official description

Draytek Vigor Routers firmware versions below 3.9.6/4.2.4, Access Points firmware versions below v1.4.0, Switches firmware versions below 2.6.7, and Myvigor firmware versions below 2.3.2 were discovered to use hardcoded encryption keys which allows attackers to bind any affected device to their own account. Attackers are then able to create WCF and DrayDDNS licenses and synchronize them from the website.

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

The underlying weakness: Use of Hard-coded Credentials

The product contains hard-coded credentials, such as a password or cryptographic key.

How developers prevent this class of flaw

  • For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible. In Windows environments, the Encrypted File System (EFS) may provide some protection.
  • For inbound authentication: Rather than hard-code a default username and password, key, or other authentication credentials for first time logins, utilize a first login mode that requires the user to enter a unique strong password or key.
  • If the product must contain hard-coded credentials or they cannot be removed, perform access control checks and limit which entities can access the feature that requires the hard-coded credentials. For example, a feature might only be enabled through the system console instead of through a network connection.

More Use of Hard-coded Credentials vulnerabilities (CWE-798)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Recent Use of Hard-coded Credentials vulnerabilities

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