CVE-2021-21376: Omero web OMERO.web Exposes Some Unnecessary Session Vulnerability

HIGH
Advisory Identifier: GHSA-gfp2-w5jm-955q
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CVSS 6.4
CWE-200
Published
Advisory Summary

CVE-2021-21376 is a HIGH (CVSS 6.4) omero.web exposes some unnecessary session vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Omero web libraries in the PyPI ecosystem. The issue involves omero.web exposes some unnecessary session information in the page. Remediation is available by upgrading affected packages to version 5.9.0.

CVE-2021-21376 at a Glance

CVE Identifier CVE-2021-21376
GHSA Identifier GHSA-gfp2-w5jm-955q
Severity HIGH
CVSS v3.1 Base Score 6.4
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Omero web
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2021-21376

To remediate this vulnerability, upgrade all affected Omero web dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

omero-web fixed: 5.9.0 
pip install omero-web>=5.9.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show omero-web

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2021-21376, inspect your installed packages using pip:

pip show omero-web

Analyze the terminal output to locate any version of Omero web in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.9.0), your application is affected.

Note: The pip show omero-web command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. In Omero web, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Background OMERO.web loads various information about the current user such as their id, name and the groups they are in, and these are available on the main webclient pages. Some additional information being loaded is not used by the webclient and is being removed in this release. ### 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](https://github.com/ome/omero-web) * Email us at [security](mailto:security@openmicroscopy.org.uk)

CVE-2021-21376 Affected Omero web Versions

1 component(s)
Fixed Versions:
5.9.0
Product / Package Ecosystem Affected Versions Fixed Version
omero-web
pypi/omero-web
PyPI
< 5.9.0
5.9.0

References

Omero web Security Information SECURITY
https://www.openmicroscopy.org/security/advisories/2021-SV1
GitHub Advisory / Wiki ADVISORY
https://github.com/ome/omero-web/security/advisories/GHSA-gfp2-w5jm-955q
NVD — CVE-2021-21376 NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-21376
Security Fix Commit FIX COMMIT
https://github.com/ome/omero-web/commit/952f8e5d28532fbb14fb665982211329d137908c
Omero web Source Repository REPOSITORY
https://github.com/ome/omero-web
Omero web Source Repository REPOSITORY
https://github.com/ome/omero-web/blob/master/CHANGELOG.md#590-march-2021
Omero web Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/omero-web/PYSEC-2021-31.yaml
pypi.org/project/omero-web WEB
https://pypi.org/project/omero-web

Frequently Asked Questions

What is CVE-2021-21376?
CVE-2021-21376 is a security vulnerability in Omero web involving OMERO.web exposes some unnecessary session information in the page under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Omero web versions are affected?
Affected versions include releases prior to 5.9.0 across affected packages: omero-web.
What version fixes CVE-2021-21376?
Upgrading to 5.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is omero-web affected?
Yes, omero-web is affected in releases prior to 5.9.0. Upgrade your dependency to 5.9.0 or later.
What is the CVSS score of CVE-2021-21376?
CVE-2021-21376 has a CVSS v3.1 base score of 6.4 (HIGH) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2021-21376?
CVE-2021-21376 is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor (The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.).
How can I check PyPI dependencies for CVE-2021-21376?
Run the dependency tree command: 'pip show omero-web'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gfp2-w5jm-955q",
  "modified" : "2024-10-07T21:25:28Z",
  "published" : "2021-03-23T15:26:34Z",
  "aliases" : [ "CVE-2021-21376" ],
  "summary" : "OMERO.web exposes some unnecessary session information in the page",
  "details" : "### Background\nOMERO.web loads various information about the current user such as their id, name and the groups they are in, and these are available on the main webclient pages. Some additional information being loaded is not used by the webclient and is being removed in this release.\n\n### Impact\nOMERO.web before 5.9.0\n\n### Patches\n5.9.0\n\n### Workarounds\nNo workaround\n\n### References\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [omero-web](https://github.com/ome/omero-web)\n* Email us at [security](mailto:security@openmicroscopy.org.uk)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "omero-web"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ome/omero-web/security/advisories/GHSA-gfp2-w5jm-955q"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-21376"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ome/omero-web/commit/952f8e5d28532fbb14fb665982211329d137908c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ome/omero-web"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ome/omero-web/blob/master/CHANGELOG.md#590-march-2021"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/omero-web/PYSEC-2021-31.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://pypi.org/project/omero-web"
  }, {
    "type" : "WEB",
    "url" : "https://www.openmicroscopy.org/security/advisories/2021-SV1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-03-23T15:25:08Z",
    "nvd_published_at" : "2021-03-23T16:15:00Z"
  }
}