#VU26721 Path traversal in Nebula - CVE-2020-11498

Vulnerability identifier: #VU26721

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-11498

CWE-ID: CWE-22

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Nebula
Web applications / Modules and components for CMS

Vendor: Slack Technologies, Inc.

Description

The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in "tun_darwin.go" and "tun_windows.go" file. A remote authenticated attacker can send a specially crafted HTTP request and read arbitrary files on the system.

Successful exploitation of this vulnerability may lead to remote code execution.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Nebula: 1.0.0 - 1.1.0

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External links
https://www.pwn3d.org/posts/7918501-slack-nebula-relative-path-bug-bounty-disclosure
https://github.com/slackhq/nebula/pull/191

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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.