CVE-2019-13115

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.

Summary:

In libssh2 before 1.9.0, kex_method_diffie_hellman_group_exchange_sha256_key_exchange in kex.c has an integer overflow that could lead to an out-of-bounds read in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to disclose sensitive information or cause a denial of service condition on the client system when a user connects to the server. This is related to an _libssh2_check_length mistake, and is different from the various issues fixed in 1.8.1, such as CVE-2019-3855.

Reference Links(if available):

  • https://github.com/libssh2/libssh2/pull/350
  • https://blog.semmle.com/libssh2-integer-overflow/
  • https://github.com/libssh2/libssh2/compare/02ecf17…42d37aa
  • https://libssh2.org/changes.html
  • https://lists.debian.org/debian-lts-announce/2019/07/msg00024.html
  • CVSS Score (if available)

    v2: / MEDIUMAV:N/AC:M/Au:N/C:P/I:N/A:P

    v3: / HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

    Links to Exploits(if available)