Security readout for executives and security teams
Plain-English summary
This issue weakens the expected security benefit of enabling two-factor authentication in Redmine. In Redmine 4.2.0 and 4.2.1, already-active sessions can remain valid after 2FA is enabled, so an existing logged-in browser session may bypass the new control until it expires or is revoked.
Executive priority
Treat this as a moderate-priority identity control issue. It does not prove external exploitation, but it can undermine a 2FA rollout for Redmine and should be handled promptly for privileged users and internet-accessible instances.
Technical view
CVE-2021-37156 describes a session lifecycle flaw in Redmine 4.2.0 and 4.2.1. When 2FA is enabled for an account, existing sessions should be terminated, but affected versions allow them to continue. The provided sources do not include CVSS, CWE, patch details, or exploit evidence.
Likely exposure
Exposure is limited to organizations running Redmine 4.2.0 or 4.2.1, especially where 2FA rollout was used to reduce account compromise risk. The issue matters most if accounts had active sessions before 2FA enrollment.
Exploitation context
The source bundle does not show active exploitation, public exploit availability, or CISA KEV listing. The risk is mainly control bypass through pre-existing authenticated sessions, not a standalone unauthenticated compromise path based on the supplied evidence.
Researcher notes
Evidence is sparse: the CVE description identifies affected Redmine versions and behavior, but no CVSS, CWE, exploit status, or fixed version is included in the supplied bundle. Validate against Redmine’s advisory before asserting remediation specifics.
Mitigation direction
- Review Redmine’s security advisory and release note for vendor-approved remediation.
- Upgrade or patch Redmine according to confirmed vendor guidance.
- Do not assume 2FA enrollment invalidates active sessions on affected versions.
- Manually revoke or expire active sessions after 2FA enrollment where supported.
- Prioritize accounts with administrative or project-management privileges.
Validation and detection
- Inventory Redmine instances and confirm whether versions 4.2.0 or 4.2.1 are present.
- Review 2FA enrollment dates for privileged Redmine accounts.
- Check whether active sessions persisted after 2FA enablement.
- Confirm session revocation behavior after applying vendor guidance.
- Document compensating controls for any instance awaiting remediation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-37156 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.redmine.org/projects/redmine/wiki/Security_AdvisoriesCVE reference · x_refsource_MISC
- https://www.redmine.org/news/132CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.