Debian 8 Jessie: DLA-1730-3 Moderate: Libssh2 Security Fix

CVE-2019-3859

While investigating the impact of CVE-2019-13115 in Debian jessie's
version of libssh2, it was discovered that issues around
CVE-2019-3859 had not been fully resolved in Debian jessie's version
of libssh2. A thorough manual (read, analyze, and copy code changes
if needed) comparison of upstream code and code in Debian jessie's
version of libssh2 was done and various more boundary checks and
integer overflow protections got added to the package.

CVE-2019-13115

Kevin Backhouse from semmle.com discovered that initial fixes for the
CVE series CVE-2019-3855 - 2019-3863 introduced several regressions
about signedness of length return values into the upstream code.
While working on the CVE-2019-3859 update mentioned above, it was
paid attention to not introduce these upstream regression registered
as CVE-2019-13115.

For Debian 8 "Jessie", these problems have been fixed in version
1.4.3-4.1+deb8u4.