CVE-2021-39371

An XML external entity (XXE) injection in PyWPS before 4.4.5 allows an attacker to view files on the application server filesystem by assigning a path to the entity. OWSLib 0.24.1 may also be affected.

Published: 2021-08-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-39371 is rated Moderate Risk (55.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.47%). Review affected assets and schedule remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2021-39371

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 2026-06-15 0.53% 1.47% +0.95%
2 2025-12-28 0.45% 0.53% +0.08%
3 2025-12-27 — 0.45% —

Full EPSS history (23 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-39371

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N 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:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N 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:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-39371

GitHub Security Advisory for CVE-2021-39371

GHSA-p9wf-3xpg-c9g5 · Severity: high · Ecosystem: pip — XML External Entity Injection in PyWPS

OS Trackers for CVE-2021-39371

vendor priority summary link
debian not yet assigned CVE-2021-39371 not yet assigned priority: Debian including 1 source packages (pywps), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-39371
ubuntu medium CVE-2021-39371 medium priority: Ubuntu including 1 source packages (pywps), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 6, ignored 4, needs-triage 3, DNE 1, released 1. https://ubuntu.com/security/CVE-2021-39371

Affected software / configurations for CVE-2021-39371

Vendor Product Version Raw CPE
osgeo owslib 0.24.1 cpe:2.3:a:osgeo:owslib:0.24.1:*:*:*:*:*:*:*
osgeo pywps < 4.4.5 cpe:2.3:a:osgeo:pywps:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2021-39371

URL Tags
https://github.com/geopython/OWSLib/issues/790 Issue Tracking Patch Third Party Advisory
https://github.com/geopython/pywps/pull/616 Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/09/msg00001.html Mailing List Third Party Advisory
cvelogic Threat Intelligence