CVE-2021-33511
Server-Side Request Forgery in Plone
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2021-33511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:P/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2021-33511- Updated
- 2026-11-02
EUVDEUVD-2021-0193 No score
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.
- Record
EUVD-2021-0193- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gc9g-67cq-p7v4
Server-Side Request Forgery in Plone
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.
- Record
GHSA-gc9g-67cq-p7v4- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2021-33511- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-gc9g-67cq-p7v4
Server-Side Request Forgery in Plone
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.
- Record
GHSA-gc9g-67cq-p7v4- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-918
- Updated
- 2026-11-02
OSVPYSEC-2021-83 No score
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.
- Record
PYSEC-2021-83- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
plonePyPI |
through 5.2.4 | None known |
plonePyPI |
through 5.2.4, plus listed versions 3.23.2.13.2.23.2.33.2a1 Show 45 moreShow less3.2rc13.33.3.13.3.23.3.33.3.43.3.53.3.63.3b13.3rc13.3rc23.3rc33.3rc43.3rc54.04.0.14.0.104.0.24.0.34.0.44.0.54.0.64.0.74.0.84.0.94.0a14.0a24.0a34.0a44.0a54.0b14.0b24.0b34.0b44.0b54.0rc14.14.1.14.1.24.1.34.1.44.1.54.1.64.1a14.1a2 |
None known |
plonePyPI |
before 5.2.5, plus listed versions 3.23.2.13.2.23.2.33.2a1 Show 45 moreShow less3.2rc13.33.3.13.3.23.3.33.3.43.3.53.3.63.3b13.3rc13.3rc23.3rc33.3rc43.3rc54.04.0.14.0.104.0.24.0.34.0.44.0.54.0.64.0.74.0.84.0.94.0a14.0a24.0a34.0a44.0a54.0b14.0b24.0b34.0b44.0b54.0rc14.14.1.14.1.24.1.34.1.44.1.54.1.64.1a14.1a2 |
5.2.5 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-33511 is a high vulnerability (CVSS 7.5) in Plone, published May 21, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.16%, the 67th percentile. Fixed in plone 5.2.5.
References
Left out here: 189 versions. The JSON record has them.