#VU45744 UNIX symbolic link following in Net-snmp - CVE-2020-15861

Vulnerability identifier: #VU45744

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-2020-15861

CWE-ID: CWE-61

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Net-snmp
Server applications / Remote management servers, RDP, SSH

Vendor: net-snmp.sourceforge.net

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a symlink following issue in snmpd. A local user can bypass implemented security mechanism via *snmp-mibs-downloader package* and execute arbitrary commands on the system as root.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Net-snmp: 5.0 - 5.8.pre3

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External links
https://github.com/net-snmp/net-snmp/commit/4fd9a450444a434a993bc72f7c3486ccce41f602
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=966599

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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.