CVE-2021-31800 Path traversal in impacket

What is CVE-2021-31800?

CVE-2021-31800 is a critical path traversal vulnerability in Fedoraproject Fedora, published on 5 May 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Multiple path traversal vulnerabilities exist in smbserver.py in Impacket through 0.9.22. An attacker that connects to a running smbserver instance can list and write to arbitrary files via ../ directory traversal. This could potentially be abused to achieve arbitrary code execution by replacing /etc/shadow or an SSH authorized key.

Weakness: CWE-22

Which versions are affected by CVE-2021-31800?

3 open source packages ship an affected version, including impacket. It affects 2 products.

Products include Fedoraproject Fedora, Secureauth Impacket.

How do I fix CVE-2021-31800?

Upgrade impacket to 0.9.23 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2021-31800 being exploited?

There is no known exploitation of CVE-2021-31800 in the wild and no public exploit code.

Public exploit code: 2 proofs of concept on GitHub.

Other vulnerabilities in Fedoraproject Fedora

• CVE-2024-4577 PHP-CGI OS Command Injection Exploited Critical 9.8
• CVE-2021-39226 Grafana Authentication Bypass Exploited Critical 9.8
• CVE-2019-5544 VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Exploited Critical 9.8
• CVE-2024-4947 Google Chromium V8 Type Confusion Exploited Critical 9.6
• CVE-2024-4671 Google Chromium Visuals Use-After-Free Exploited Critical 9.6

All Fedoraproject Fedora vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2021-31800, GHSA-mj63-64x7-57xf, PYSEC-2021-17, UBUNTU-CVE-2021-31800, openSUSE-SU-2024:11232-1, openSUSE-SU-2024:14142-1.