ALAS2-2019-1199

Amazon Linux 2 Security Advisory: ALAS-2019-1199
Advisory Release Date: 2019-04-25 16:44 Pacific
Advisory Updated Date: 2019-04-26 01:32 Pacific
Severity: Important
Issue Overview:

An integer overflow flaw, which could lead to an out of bounds write, was discovered in libssh2 in the way keyboard prompt requests are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.(CVE-2019-3856)

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 in the way packets are read from the server. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.(CVE-2019-3855)

A vulnerability was found in in libssh2 where a server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used as an index to copy memory causing in an out of bounds memory write error.(CVE-2019-3863)

An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.(CVE-2019-3857)


Affected Packages:

libssh2


Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.


Issue Correction:
Run yum update libssh2 to update your system.

New Packages:
aarch64:
    libssh2-1.4.3-12.amzn2.2.aarch64
    libssh2-devel-1.4.3-12.amzn2.2.aarch64
    libssh2-debuginfo-1.4.3-12.amzn2.2.aarch64

i686:
    libssh2-1.4.3-12.amzn2.2.i686
    libssh2-devel-1.4.3-12.amzn2.2.i686
    libssh2-debuginfo-1.4.3-12.amzn2.2.i686

noarch:
    libssh2-docs-1.4.3-12.amzn2.2.noarch

src:
    libssh2-1.4.3-12.amzn2.2.src

x86_64:
    libssh2-1.4.3-12.amzn2.2.x86_64
    libssh2-devel-1.4.3-12.amzn2.2.x86_64
    libssh2-debuginfo-1.4.3-12.amzn2.2.x86_64

Additional References

Red Hat: CVE-2019-3855, CVE-2019-3856, CVE-2019-3857, CVE-2019-3863

Mitre: CVE-2019-3855, CVE-2019-3856, CVE-2019-3857, CVE-2019-3863