CVE-2021-21377 json
Open Redirect in OMERO.web
published 2021-03-23 5 y ago modified 2026-07-08 4 mo ago also GHSA-g4rf-pc26-6hmr , PYSEC-2021-32 , EUVD-2021-0158
- cvss
- 4.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.8%
- EPSS 0.8% chance of exploitation in 30 days, percentile 57%
- public exploits
- 0
- none known
Summary
OMERO.web is open source Django-based software for managing microscopy imaging. OMERO.web before version 5.9.0 supports redirection to a given URL after performing login or switching the group context. These URLs are not validated, allowing redirection to untrusted sites. OMERO.web 5.9.0 adds URL validation before redirecting. External URLs are not considered valid, unless specified in the omero.web.redirect_allowed_hosts setting.
Patch / fix
Exploit prediction
0.83% chance of exploitation in the next 30 days, higher than 57% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N |
| NVD | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.9 | AV:N/AC:M/Au:S/C:P/I:P/A:N |
| GitHub | 3.1 | 4.8 | CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | omero-web | <5.9.0 |
5.9.0 |
Affected products
- ome omero-web
Classification
- Weakness
-
- CWE-601 URL Redirection to Untrusted Site
References
-
github.com
/ome/omero-web/commit/952f8e5d28532fbb14fb665982211329d137908c
web, patch, third-party-advisory
-
openmicroscopy.org
/security/advisories/2021-SV2/
vendor-advisory, advisory
-
pypi.org
/project/omero-web/
third-party-advisory, package
-
github.com
/ome/omero-web/blob/master/CHANGELOG.md#590-march-2021
web, release-notes, third-party-advisory
-
github.com
/ome/omero-web/security/advisories/GHSA-g4rf-pc26-6hmr
web, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2021-21377
advisory
-
github.com
/ome/omero-web
package
-
github.com
/pypa/advisory-database/tree/main/vulns/omero-web/PYSEC-2021-32.yaml
web
-
pypi.org
/project/omero-web
web
-
openmicroscopy.org
/security/advisories/2021-SV2
web
Sources
- CVE List CVE-2021-21377
- GitHub Advisory GHSA-g4rf-pc26-6hmr
- NVD CVE-2021-21377
- OSV PYSEC-2021-32
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.