RHSA-2019:1791 - Security Advisory

Topic

An update for libssh2 is now available for Red Hat Enterprise Linux 7.5 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The libssh2 packages provide a library that implements the SSH2 protocol.

Security Fix(es):

• libssh2: Integer overflow in transport read resulting in out of bounds write (CVE-2019-3855)
• libssh2: Integer overflow in keyboard interactive handling resulting in out of bounds write (CVE-2019-3856)
• libssh2: Integer overflow in SSH packet processing channel resulting in out of bounds write (CVE-2019-3857)
• libssh2: Integer overflow in user authenticate keyboard interactive allows out-of-bounds writes (CVE-2019-3863)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing these updated packages, all running applications using libssh2 must be restarted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le

Fixes

• BZ - 1687303 - CVE-2019-3855 libssh2: Integer overflow in transport read resulting in out of bounds write
• BZ - 1687304 - CVE-2019-3856 libssh2: Integer overflow in keyboard interactive handling resulting in out of bounds write
• BZ - 1687305 - CVE-2019-3857 libssh2: Integer overflow in SSH packet processing channel resulting in out of bounds write
• BZ - 1687313 - CVE-2019-3863 libssh2: Integer overflow in user authenticate keyboard interactive allows out-of-bounds writes

CVEs

• CVE-2019-3855
• CVE-2019-3856
• CVE-2019-3857
• CVE-2019-3863

References

• https://access.redhat.com/security/updates/classification/#important