OMERO webclient does not validate URL redirects on login or switching group.

CVE-2021-21377 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Background

OMERO.web 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.

Impact

OMERO.web before 5.9.0

Patches

5.9.0

Workarounds

No workaround

References

For more information

If you have any questions or comments about this advisory:
* Open an issue in omero-web
* Email us at security

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2021-03-23 15:26:49 UTC
Updated
2024-10-08 12:43:20 UTC
GitHub reviewed
2021-03-23 15:25:55 UTC
NVD published
2021-03-23

EPSS Score

Score Percentile
0.31% 54.54%

CVSS Scores

Base score Version Severity Vector
4.8 3.1 —
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:N/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:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
5.9 4.0 —
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:P)
A user has to participate (for example click/open/approve).
Vulnerable system confidentiality impact (VC:H)
High confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:N)
No confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:N)
No integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-g4rf-pc26-6hmr ↗
CVE CVE-2021-21377 ↗

CWEs

CWE id Name
CWE-601 URL Redirection to Untrusted Site ('Open Redirect')

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip omero-web < 5.9.0 5.9.0 —

References

cvelogic Threat Intelligence