CVE-2022-25219

Description

A null byte interaction error has been discovered in the code that the telnetd_startup daemon uses to construct a pair of ephemeral passwords that allow a user to spawn a telnet service on the router, and to ensure that the telnet service persists upon reboot. By means of a crafted exchange of UDP packets, an unauthenticated attacker on the local network can leverage this null byte interaction error in such a way as to make those ephemeral passwords predictable (with 1-in-94 odds). Since the attacker must manipulate data processed by the OpenSSL function RSA_public_decrypt(), successful exploitation of this vulnerability depends on the use of an unpadded RSA cipher (CVE-2022-25218).

References

ExploitThird Party Advisory

CvssV3 impact

BaseSeverity

HIGH

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

UNCHANGED

AttackVector

LOCAL

AvailabilityImpact

HIGH

IntegrityImpact

HIGH

PrivilegesRequired

NONE

BaseScore

8.4

VectorString

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

MEDIUM

ConfidentialityImpact

COMPLETE

AvailabilityImpact

COMPLETE

IntegrityImpact

COMPLETE

BaseScore

6.9

VectorString

AV:L/AC:M/Au:N/C:C/I:C/A:C

Version

2.0

AccessVector

LOCAL

Authentication

NONE