Improper physical access control and use of hard-coded credentials in /etc/passwd permits an attacker with physical access to obtain a root
Improper physical access control and use of hard-coded credentials in /etc/passwd permits an attacker with physical access to obtain a root shell via an unprotected UART port on the device. The same port exposes an unauthenticated Das U-Boot BIOS shell.
- Published
- Mar 10, 2022
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 28th percentile
- CWE
- CWE-798
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Report tools
Action score
27
Monitor
Low priority for now.
- CVSS
- 27 / 40 · 6.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| phicomm | k2 firmware | cpe:2.3:o:phicomm:k2_firmware |
| phicomm | k2 | cpe:2.3:h:phicomm:k2 |
| phicomm | k3 firmware | cpe:2.3:o:phicomm:k3_firmware |
| phicomm | k3 | cpe:2.3:h:phicomm:k3 |
| phicomm | k3c firmware | cpe:2.3:o:phicomm:k3c_firmware |
| phicomm | k3c | cpe:2.3:h:phicomm:k3c |
| phicomm | k2g firmware | cpe:2.3:o:phicomm:k2g_firmware |
| phicomm | k2g | cpe:2.3:h:phicomm:k2g |
| phicomm | k2p firmware | cpe:2.3:o:phicomm:k2p_firmware |
| phicomm | k2p | cpe:2.3:h:phicomm:k2p |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- phicomm k2 firmwareup to 22.5.9.163 inclusive
- phicomm k2g firmwareup to 22.6.3.20 inclusive
- phicomm k2p firmwareup to 20.4.1.7 inclusive
- phicomm k3 firmwareup to 21.5.37.246 inclusive
- phicomm k3c firmwareup to 32.1.15.93 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (tenable). Independent of NVD's CPE analysis and usually ahead of it.
n/a Phicomm Routers
- K3Caffected
Same product
phicomm: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-25219A null byte interaction error has been discovered in the code that the telnetd_startup daemon uses to construct a pair of ephemeral password33Monitor
- CVE-2022-25218The use of the RSA algorithm without OAEP, or any other padding scheme, in telnetd_startup, allows an unauthenticated attacker on the local 32Monitor
- CVE-2023-40796Phicomm k2 v22.6.529.216 was discovered to contain a command injection vulnerability via the function luci.sys.call.31Monitor
- CVE-2022-48072Phicomm K2G v22.6.3.20 was discovered to contain a command injection vulnerability via the autoUpTime parameter in the automatic upgrade fun31Monitor
- CVE-2022-48070Phicomm K2 v22.6.534.263 was discovered to contain a command injection vulnerability via the autoUpTime parameter in the automatic upgrade f31Monitor
- CVE-2022-25217Use of a hard-coded cryptographic key pair by the telnetd_startup service allows an attacker on the local area network to obtain a root shel31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Physical access to the device is required.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Physical
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-798 · Use of Hard-coded CredentialsCVSS vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Root cause
For convenience in support or manufacturing, an account that is identical on every device is embedded in the software. Credentials learned from one device work on all of them.
The bug in code
The whole CWE-798 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const SUPPORT_USER = "support";const SUPPORT_PASS = "hardcoded-password";Fixed
const creds = await provisioning.deviceCredentials(deviceId);if (creds.mustRotate) await forcePasswordChange(deviceId);Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.