#VU115176 NULL pointer dereference in libssh - CVE-2015-3146

Vulnerability identifier: #VU115176

Vulnerability risk: Medium

CVSSv4.0: 1.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-3146

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
libssh
Universal components / Libraries / Libraries used by multiple products

Vendor: libssh

Description

The vulnerability allows a remote user to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error when handling SSH_MSG_NEWKEYS and SSH_MSG_KEXDH_REPLY packets in package_cb.c. A remote user can trigger denial of service conditions via a crafted SSH packet.

Mitigation
Install update from vendor's website.

Vulnerable software versions

libssh: 0.3.0 - 0.6.4

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External links
https://lists.fedoraproject.org/pipermail/package-announce/2015-July/161802.html
https://lists.fedoraproject.org/pipermail/package-announce/2015-May/158013.html
https://www.debian.org/security/2016/dsa-3488
https://www.ubuntu.com/usn/USN-2912-1
https://git.libssh.org/projects/libssh.git/commit/?h=libssh-0.6.5&id=94f6955fbaee6fda9385a23e505497efe21f5b4f
https://www.libssh.org/2015/04/30/libssh-0-6-5-security-and-bugfix-release/
https://www.libssh.org/security/advisories/CVE-2015-3146.txt

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.