CVE-2022-25219

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).

• phicomm k2 firmware (<= 22.5.9.163) • phicomm k3 firmware (<= 21.5.37.246) • phicomm k3c firmware (<= 32.1.15.93) • phicomm k2g firmware (<= 22.6.3.20) • phicomm k2p firmware (<= 20.4.1.7)