#VU14820 Double Free in Dropbear - CVE-2017-9078

Vulnerability identifier: #VU14820

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-9078

CWE-ID: CWE-415

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Dropbear
Server applications / Remote management servers, RDP, SSH

Vendor: Matt Johnston

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a double free in cleanup of TCP listeners when the -a option is enabled. The vulnerability allows a remote authenticated attacker to trigger double free error and execute arbitrary code on the target system with root privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Dropbear: 2013.56 - 2016.74

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External links
https://lists.ucc.gu.uwa.edu.au/pipermail/dropbear/2017q2/001985.html
https://www.debian.org/security/2017/dsa-3859

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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