CVE-2022-25219Public exploit

Unauthenticated root shell via null-truncated password hashing

Published Mar 7, 2022 · Updated Aug 3, 2024

Predictable password generation in the telnetd_startup daemon in Phicomm routers allows remote attackers to obtain a root shell via UDP packets. After attacker-controlled RSA output is XORed with a random secret, sprintf treats a leading null as an empty %s string and hashes only the +TEMP or +PERM salt. Access requires the local network and an unpadded RSA operation from CVE-2022-25218; without rate limiting, a successful 1-in-94 collision yields temporary or persistent root access.

CVSS severity8.4
High
EPSS probability0.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Predictable password generation in the telnetd_startup daemon in Phicomm routers allows remote attackers to obtain a root shell via UDP packets. After attacker-controlled RSA output is XORed with a random secret, sprintf treats a leading null as an empty %s string and hashes only the +TEMP or +PERM salt. Access requires the local network and an unpadded RSA operation from CVE-2022-25218; without rate limiting, a successful 1-in-94 collision yields temporary or persistent root access.

The record

CVE
CVE-2022-25219
Published
Mar 7, 2022
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1059.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 7, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.4NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.9NIST NVDAV:L/AC:M/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1059.004Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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