Security update for openssh

SUSE Security Update: Security update for openssh
Announcement ID: SUSE-SU-2018:3540-1
Rating: important
References: #1016370 #1065000 #1076957 #1105010 #1105180 #1106163 #1106726
Cross-References: CVE-2016-10012 CVE-2016-10708 CVE-2017-15906 CVE-2018-15473 CVE-2018-15919
Affected Products:
  • SUSE Linux Enterprise Server 11-SP3-LTSS
  • SUSE Linux Enterprise Point of Sale 11-SP3
  • SUSE Linux Enterprise Debuginfo 11-SP3

An update that solves 5 vulnerabilities and has two fixes is now available.

Description:

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)

Patch Instructions:

To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
Alternatively you can run the command listed for your product:

  • SUSE Linux Enterprise Server 11-SP3-LTSS:
    zypper in -t patch slessp3-openssh-13848=1
  • SUSE Linux Enterprise Point of Sale 11-SP3:
    zypper in -t patch sleposp3-openssh-13848=1
  • SUSE Linux Enterprise Debuginfo 11-SP3:
    zypper in -t patch dbgsp3-openssh-13848=1

Package List:

  • SUSE Linux Enterprise Server 11-SP3-LTSS (i586 s390x x86_64):
    • openssh-6.2p2-0.41.5.1
    • openssh-askpass-6.2p2-0.41.5.1
    • openssh-askpass-gnome-6.2p2-0.41.5.1
  • SUSE Linux Enterprise Point of Sale 11-SP3 (i586):
    • openssh-6.2p2-0.41.5.1
    • openssh-askpass-6.2p2-0.41.5.1
    • openssh-askpass-gnome-6.2p2-0.41.5.1
  • SUSE Linux Enterprise Debuginfo 11-SP3 (i586 s390x x86_64):
    • openssh-askpass-gnome-debuginfo-6.2p2-0.41.5.1
    • openssh-debuginfo-6.2p2-0.41.5.1
    • openssh-debugsource-6.2p2-0.41.5.1

References: