Important: libssh2

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