CVE-2021-39271

Exp

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 update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-39271 is rated High Exploit Risk (75.8/100): CVSS High severity, with medium exploitation likelihood (EPSS 3.98%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-39271

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-39271

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-03-30 12.40% 3.98% -8.42%
2 2025-03-29 3.98% 12.40% +8.42%
3 2025-03-17 — 3.98% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-39271

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
6.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 6.4 [email protected]

Weakness enumeration for CVE-2021-39271

Affected software / configurations for CVE-2021-39271

Vendor Product Version Raw CPE
bscw bscw_classic < 5.0.12 cpe:2.3:a:bscw:bscw_classic:*:*:*:*:*:*:*:*
bscw bscw_classic >= 5.1.0, < 5.1.10 cpe:2.3:a:bscw:bscw_classic:*:*:*:*:*:*:*:*
bscw bscw_classic >= 5.2.0, < 5.2.4 cpe:2.3:a:bscw:bscw_classic:*:*:*:*:*:*:*:*
bscw bscw_classic >= 7.3.0, < 7.3.3 cpe:2.3:a:bscw:bscw_classic:*:*:*:*:*:*:*:*
bscw bscw_classic >= 7.4.0, < 7.4.3 cpe:2.3:a:bscw:bscw_classic:*:*:*:*:*:*:*:*

References for CVE-2021-39271

URL Tags
http://packetstormsecurity.com/files/163989/BSCW-Server-Remote-Code-Execution.html Exploit Mailing List Third Party Advisory
https://seclists.org/fulldisclosure/2021/Aug/24 Exploit Mailing List Third Party Advisory
https://www.bscw.de/en/company/ Vendor Advisory
cvelogic Threat Intelligence