The use of the RSA algorithm without OAEP, or any other padding scheme, in telnetd_startup, allows an unauthenticated attacker on the local
The use of the RSA algorithm without OAEP, or any other padding scheme, in telnetd_startup, allows an unauthenticated attacker on the local area network to achieve a significant degree of control over the "plaintext" to which an arbitrary blob of ciphertext will be decrypted by OpenSSL's RSA_public_decrypt() function. This weakness allows the attacker to manipulate the various iterations of the telnetd startup state machine and eventually obtain a root shell on the device, by means of an exchange of crafted UDP packets. In all versions but K2 22.5.9.163 and K3C 32.1.15.93 a successful attack also requires the exploitation of a null-byte interaction error (CVE-2022-25219).
- Published
- Mar 10, 2022
- Updated
- Jun 17, 2026
- EPSS
- 1.0% · 61th percentile
- CWE
- CWE-327
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Report tools
Action score
32
Monitor
Low priority for now.
- CVSS
- 32 / 40 · 8.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
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
- K2 >= 22.5.9.163, K3 >= 21.5.37.246, K3C >= 32.1.15.93, K2P >= 20.4.1.7, K2 A7 >= 22.6.506.28affected
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-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
- CVE-2022-48073Phicomm K2G v22.6.3.20 was discovered to store the root and admin passwords in plaintext.30Monitor
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
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
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
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-327 · Use of a Broken or Risky Cryptographic AlgorithmCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Encryption Brute ForcingCAPEC-20likelihood: Low · Low
- Creating a Rogue Certification Authority CertificateCAPEC-459likelihood: Medium · Very High
- Signature SpoofCAPEC-473
- Signature Spoofing by Improper ValidationCAPEC-475likelihood: Low · High
- Cryptanalysis of Cellular EncryptionCAPEC-608High
- Rooting SIM CardsCAPEC-614High
- CryptanalysisCAPEC-97likelihood: Low · Very High
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.