CVE-2021-32806 | URL Redirection to Untrusted Site ('Open Redirect') in Products.isurlinportal

Products.isurlinportal is a replacement for isURLInPortal method in Plone. Versions of Products.isurlinportal prior to 1.2.0 have an Open Redirect vulnerability. Various parts of Plone use the 'is url in portal' check for security, mostly to see if it is safe to redirect to a url. A url like `https://example.org` is not in the portal. The url `https:example.org` without slashes is considered to be in the portal. When redirecting, some browsers go to `https://example.org`, others give an error. Attackers may use this to redirect victims to their site, especially as part of a phishing attack. The problem has been patched in Products.isurlinportal 1.2.0.

Published: 2021-08-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-32806 is rated Moderate Risk (44.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.30%). Mandatory action: 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-2021-32806

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 2025-03-17 0.07% 0.30% +0.23%
2 2023-03-07 0.95% 0.07% -0.88%
3 2022-04-01 0.95%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-32806

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 3.6 [email protected]
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-2021-32806

GitHub Security Advisory for CVE-2021-32806

GHSA-q3m9-9fj2-mfwr · Severity: high · Ecosystem: pip — URL Redirection to Untrusted Site ('Open Redirect') in Products.isurlinportal

Affected software / configurations for CVE-2021-32806

Vendor Product Version Raw CPE
plone isurlinportal < 1.2.0 cpe:2.3:a:plone:isurlinportal:*:*:*:*:*:plone:*:*

References for CVE-2021-32806

cvelogic Threat Intelligence