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).
CPE | Name | Operator | Version |
---|---|---|---|
k2_firmware | le | 22.5.9.163 | |
k2g_firmware | le | 22.6.3.20 | |
k2p_firmware | le | 20.4.1.7 | |
k3_firmware | le | 21.5.37.246 | |
k3c_firmware | le | 32.1.15.93 |