CVE-2020-28724

Exp

Open redirect vulnerability in werkzeug before 0.11.6 via a double slash in the URL.

Published: 2020-11-18 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-28724 is rated High Exploit Risk (65.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.66%). 1 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-2020-28724

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

Exploit prediction scoring system (EPSS) score for CVE-2020-28724

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 0.92% 1.66% +0.74%
2 2025-11-21 0.56% 0.92% +0.36%
3 2025-11-18 — 0.56% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-28724

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2020-28724

GitHub Security Advisory for CVE-2020-28724

OS Trackers for CVE-2020-28724

vendor priority summary link
debian not yet assigned CVE-2020-28724 not yet assigned priority: Debian including 1 source packages (python-werkzeug), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-28724
redhat medium — https://access.redhat.com/security/cve/CVE-2020-28724
suse medium CVE-2020-28724 severity moderate: SUSE including 2 source package names (python-Werkzeug, python3-Werkzeug), 18 product×package rows across 12 product lines (HPE Helion OpenStack 8, SUSE Linux Enterprise High Performance Computing 15-LTSS, … (12 product lines)): Known Not Affected 18. https://www.suse.com/security/cve/CVE-2020-28724/
ubuntu medium CVE-2020-28724 medium priority: Ubuntu including 1 source packages (python-werkzeug), 6 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): not-affected 3, released 2, DNE 1. https://ubuntu.com/security/CVE-2020-28724

Affected software / configurations for CVE-2020-28724

Vendor Product Version Raw CPE
palletsprojects werkzeug < 0.11.6 cpe:2.3:a:palletsprojects:werkzeug:*:*:*:*:*:*:*:*

References for CVE-2020-28724

URL Tags
https://github.com/pallets/flask/issues/1639 Exploit Issue Tracking Third Party Advisory
https://github.com/pallets/werkzeug/issues/822 Issue Tracking Third Party Advisory
https://github.com/pallets/werkzeug/pull/890/files Patch Third Party Advisory
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