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Use of a Broken or Risky Cryptographic Algorithm


Severity High
Score 8.1/10


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 and K3C a successful attack also requires the exploitation of a null-byte interaction error (CVE-2022-25219).

  • HIGH
  • HIGH
  • NONE
  • NONE
  • HIGH
  • HIGH

CWE-327 - Use of a Broken or Risky Cryptographic Algorithm

The use of a broken or risky cryptographic algorithm is an unnecessary risk that may result in the exposure of sensitive information.


Advisory Timeline

  • Published