CyberSecBulletin
CVE-2022-25217NVD status: Modified

Phicomm Routers: Use of Hard-coded Credentials

CVE-2022-25217 is a high-severity use of hard-coded credentials vulnerability in Phicomm Routers, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.33% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Phicomm Routers you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
Phicomm RoutersPhicomm RoutersNot specified in the recordNot stated
PhicommK2 Firmware22.5.9.163 and earlierNot stated
PhicommK3c Firmware32.1.15.93 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighNVD
CVSS 2.07.2HighNVD

Official description

Use of a hard-coded cryptographic key pair by the telnetd_startup service allows an attacker on the local area network to obtain a root shell on the device over telnet. The builds of telnetd_startup included in the version 22.5.9.163 of the K2 firmware, and version 32.1.15.93 of the K3C firmware (possibly amongst many other releases) included both the private and public RSA keys. The remaining versions cited here redacted the private key, but left the public key unchanged. An attacker in possession of the leaked private key may, through a scripted exchange of UDP packets, instruct telnetd_startup to spawn an unauthenticated telnet shell as root, by means of which they can then obtain complete control of the device. A consequence of the limited availablility of firmware images for testing is that models and versions not listed here may share this vulnerability.

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. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in Phicomm Routers

All Phicomm Routers vulnerabilities

Recent Use of Hard-coded Credentials vulnerabilities

Spotted an error? Tell us.