What is CVE-2021-39271?

CVE-2021-39271 is a high-severity vulnerability in Bscw Classic. CVSS score: 8.8/10. Published 2021-08-30.

How severe is CVE-2021-39271?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-39271 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Bscw Classic

CVE-2021-39271

OrbiTeam BSCW Classic before 7.4.3 allows authenticated remote code execution (RCE) during archive extraction via attacker-supplied Python code in the class attribute of a .bscw file. This is fixed in 5.0.12, 5.1.10, 5.2.4, 7.3.3, and 7.4.3.

Published 2021-08-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.037 (89.3th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.037 · newest: 0.037 · change: 0.000

Affected products

Bscw Classic

Public proof-of-concept exploits

n0-traces/cve_

References

www.bscw.de/en/company/ (Vendor Advisory)
seclists.org/fulldisclosure/2021/Aug/24 (Exploit, Mailing List, Third Party Advisory)
packetstormsecurity.com/files/163989/BSCW-Server-Remote-Code-Execution.html (Exploit, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-39271?: CVE-2021-39271 is a high-severity vulnerability in Bscw Classic. CVSS score: 8.8/10. Published 2021-08-30.
How severe is CVE-2021-39271?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-39271 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.