CVE-2018-15473

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c.

OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c (CVE-2018-15473).

This update for ssh-audit fixes the following issues:

ssh-audit was updated to version 2.5.0

• Fixed crash when running host key tests.

• Handles server connection failures more gracefully.

• Now prints JSON with indents when -jj is used (useful for debugging).

• Added MD5 fingerprints to verbose output.

• Added -d/--debug option for getting debugging output.

• Updated JSON output to include MD5 fingerprints. Note that this results in a breaking change in the 'fingerprints' dictionary format.

• Updated OpenSSH 8.1 (and earlier) policies to include rsa-sha2-512 and rsa-sha2-256.

• Added OpenSSH v8.6 & v8.7 policies.

• Added 3 new key exchanges:

  • gss-gex-sha1-eipGX3TCiQSrx573bT1o1Q==
  • gss-group1-sha1-eipGX3TCiQSrx573bT1o1Q==
  • gss-group14-sha1-eipGX3TCiQSrx573bT1o1Q==

• Added 3 new MACs:

  • hmac-ripemd160-96
  • AEAD_AES_128_GCM
  • AEAD_AES_256_GCM

Update to version 2.4.0

• Added multi-threaded scanning support.
• Added version check for OpenSSH user enumeration (CVE-2018-15473).
• Added deprecation note to host key types based on SHA-1.
• Added extra warnings for SSHv1.
• Added built-in hardened OpenSSH v8.5 policy.
• Upgraded warnings to failures for host key types based on SHA-1
• Fixed crash when receiving unexpected response during host key test.
• Fixed hang against older Cisco devices during host key test & gex test.
• Fixed improper termination while scanning multiple targets when one target returns an error.
• Dropped support for Python 3.5 (which reached EOL in Sept.2020)
• Added 1 new key exchange: [email protected].

Update to version 2.3.1

• Now parses public key sizes for [email protected] and [email protected] host key types.
• Flag [email protected] as a failure due to SHA-1 hash.
• Fixed bug in recommendation output which suppressed some algorithms inappropriately.
• Built-in policies now include CA key requirements (if certificates are in use).
• Lookup function (--lookup) now performs case-insensitive lookups of similar algorithms.
• Migrated pre-made policies from external files to internal database.
• Split single 3,500 line script into many files (by class).
• Added setup.py support
• Added 1 new cipher: [email protected].

Update to version 2.3.0

The highlight of this release is support for policy scanning (this allows an admin to test a server against a hardened/standard configuration).

• Added new policy auditing functionality to test adherence to a hardening guide/standard configuration (see -L/--list-policies, -M/--make-policy and -P/--policy).
• Created new man page (see ssh-audit.1 file).
• 1024-bit moduli upgraded from warnings to failures.
• Many Python 2 code clean-ups, testing framework improvements, pylint & flake8 fixes, and mypy type comments.
• Added feature to look up algorithms in internal database (see --lookup)
• Suppress recommendation of token host key types.
• Added check for use-after-free vulnerability in PuTTY v0.73.
• Added 11 new host key types: ssh-rsa1, [email protected], ssh-gost2001, ssh-gost2012-256, ssh-gost2012-512, spki-sign-rsa, ssh-ed448, x509v3-ecdsa-sha2-nistp256, x509v3-ecdsa-sha2-nistp384, x509v3-ecdsa-sha2-nistp521, x509v3-rsa2048-sha256.
• Added 8 new key exchanges: diffie-hellman-group1-sha256, kexAlgoCurve25519SHA256, Curve25519SHA256, gss-group14-sha256-, gss-group15-sha512-, gss-group16-sha512-, gss-nistp256-sha256-, gss-curve25519-sha256-.
• Added 5 new ciphers: blowfish, AEAD_AES_128_GCM, AEAD_AES_256_GCM, [email protected], [email protected].
• Added 3 new MACs: [email protected], hmac-sha3-224, [email protected].

• Update ssh-audit.keyring

This update for ssh-audit fixes the following issues:

ssh-audit was updated to version 2.5.0

• Fixed crash when running host key tests.

• Handles server connection failures more gracefully.

• Now prints JSON with indents when -jj is used (useful for debugging).

• Added MD5 fingerprints to verbose output.

• Added -d/--debug option for getting debugging output.

• Updated JSON output to include MD5 fingerprints. Note that this results in a breaking change in the 'fingerprints' dictionary format.

• Updated OpenSSH 8.1 (and earlier) policies to include rsa-sha2-512 and rsa-sha2-256.

• Added OpenSSH v8.6 & v8.7 policies.

• Added 3 new key exchanges:

  • gss-gex-sha1-eipGX3TCiQSrx573bT1o1Q==
  • gss-group1-sha1-eipGX3TCiQSrx573bT1o1Q==
  • gss-group14-sha1-eipGX3TCiQSrx573bT1o1Q==

• Added 3 new MACs:

  • hmac-ripemd160-96
  • AEAD_AES_128_GCM
  • AEAD_AES_256_GCM

Update to version 2.4.0

• Added multi-threaded scanning support.
• Added version check for OpenSSH user enumeration (CVE-2018-15473).
• Added deprecation note to host key types based on SHA-1.
• Added extra warnings for SSHv1.
• Added built-in hardened OpenSSH v8.5 policy.
• Upgraded warnings to failures for host key types based on SHA-1
• Fixed crash when receiving unexpected response during host key test.
• Fixed hang against older Cisco devices during host key test & gex test.
• Fixed improper termination while scanning multiple targets when one target returns an error.
• Dropped support for Python 3.5 (which reached EOL in Sept.2020)
• Added 1 new key exchange: [email protected].

These are all security issues fixed in the ssh-audit-2.5.0-1.2 package on the GA media of openSUSE Tumbleweed.

This update for openssh fixes the following issues:

Security issues fixed:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2017-15906: The process_open function in sftp-server.c in OpenSSH did not properly prevent write operations in readonly mode, which allowed attackers to create zero-length files. (bsc#1065000, bsc#1106726)
• CVE-2016-10708: sshd allowed remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via an out-of-sequence NEWKEYS message, as demonstrated by Honggfuzz, related to kex.c and packet.c. (bsc#1076957)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)
• CVE-2016-10012: Removed pre-auth compression support from the server to prevent possible cryptographic attacks. (bsc#1016370)

Bugs fixed:

• Fixed failing 'AuthorizedKeysCommand' within a 'Match User' block in sshd_config (bsc#1105180)

This update for openssh fixes the following issues:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

The following non-security issues were fixed:

• Stop leaking File descriptors (bsc#964336)
• sftp-client.c returns wrong error code upon failure (bsc#1091396)
• added pam_keyinit to pam configuration file (bsc#1081947)

This update for openssh-openssl1 fixes the following issues:

Security issues fixed:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

Following non-security issues were fixed:

• Fix for sftp client because it returns wrong error code upon failure (bsc#1091396)
• Stop leaking File descriptors (bsc#964336)

This update for openssh fixes the following issues:

Following security issues have been fixed:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

Also the following security related hardening change was done:

• Remove arcfour,cast,blowfish from list of default ciphers. (bsc#982273)

And the following non-security issues were fixed:

• Stop leaking File descriptors (bsc#964336)
• sftp-client.c returns wrong error code upon failure (bsc#1091396)

This update for openssh fixes the following issues:

Following security issues have been fixed:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

Also the following security related hardening change was done:

• Remove arcfour,cast,blowfish from list of default ciphers. (bsc#982273)

And the following non-security issues were fixed:

• Stop leaking File descriptors (bsc#964336)
• sftp-client.c returns wrong error code upon failure (bsc#1091396)

This update for openssh fixes the following issues:

Following security issues have been fixed:

• CVE-2018-15919: Remotely observable behaviour in auth-gss2.c in OpenSSH could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. OpenSSH developers do not want to treat such a username enumeration (or 'oracle') as a vulnerability. (bsc#1106163)
• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

Also the following security related hardening change was done:

• Removed arcfour,blowfish,cast from list of default ciphers as they are long discontinued and should no longer be used. (bsc#982273)

And the following non-security issues were fixed:

• Stop leaking File descriptors (bsc#964336)
• sftp-client.c returns wrong error code upon failure (bsc#1091396)

This update for openssh fixes the following issues:

Following security issues have been fixed:

• CVE-2018-15473: OpenSSH was prone to a user existance oracle vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. (bsc#1105010)

The following non-security issues were fixed:

• Stop leaking File descriptors (bsc#964336)
• sftp-client.c returns wrong error code upon failure [bsc#1091396]

Robert Swiecki discovered that OpenSSH incorrectly handled certain messages. An attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-10708)

It was discovered that OpenSSH incorrectly handled certain requests. An attacker could possibly use this issue to access sensitive information. (CVE-2018-15473)