CVE-2021-33511 json
Server-Side Request Forgery in Plone
published 2021-05-21 5 y ago modified 2026-06-17 4 mo ago also GHSA-gc9g-67cq-p7v4 , PYSEC-2021-83 , EUVD-2021-0193
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 67%
- public exploits
- 0
- none known
Summary
Plone though 5.2.4 allows SSRF via the lxml parser. This affects Diazo themes, Dexterity TTW schemas, and modeleditors in plone.app.theming, plone.app.dexterity, and plone.supermodel.
Patch / fix
- pypi plone 5.2.5
Exploit prediction
1.16% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:P/I:N/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | plone | <=5.2.4 <5.2.5 |
5.2.5 |
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
-
plone.org
/security/hotfix/20210518/server-side-request-forgery-via-lxml-parser
web, vendor-advisory
-
openwall.com
/lists/oss-security/2021/05/22/1
mailing-list, web, third-party-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-33511
advisory
-
github.com
/advisories/GHSA-gc9g-67cq-p7v4
advisory
-
github.com
/plone/Plone
package
-
github.com
/pypa/advisory-database/tree/main/vulns/plone/PYSEC-2021-83.yaml
web
Sources
- CVE List CVE-2021-33511
- GitHub Advisory GHSA-gc9g-67cq-p7v4
- NVD CVE-2021-33511
- OSV PYSEC-2021-83
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.