Security readout for executives and security teams
Plain-English summary
Discourse exposed limited information about how a user interacted with a topic, including last read post and notification level. This is privacy leakage, not system takeover. Organizations running affected Discourse versions should prioritize updating because forum activity metadata can still be sensitive.
Executive priority
Treat as a moderate privacy issue. It is not a breach indicator by itself, but affected public or private communities should update promptly to reduce avoidable metadata exposure.
Technical view
CVE-2021-37703 is CWE-200 information exposure in Discourse before 2.7.8 and 2.8.0.beta5. The exposed data is a user's read state for a topic. CVSS 3.1 is 4.3: network reachable, low complexity, user interaction required, and low confidentiality impact.
Likely exposure
Exposure is limited to organizations operating Discourse instances below the fixed versions named in the sources. The bundle does not identify affected hosted configurations, plugins, or downstream distributions.
Exploitation context
The source bundle does not report active exploitation, and KEV is false. The vulnerability concerns unintended disclosure of topic read-state metadata, not code execution, authentication bypass, data modification, or service disruption.
Researcher notes
Evidence is limited to the CVE record, GitHub advisory, and linked commit. The bundle names the exposed fields and fixed version thresholds, but does not provide exploit telemetry, broad impact analysis, or separate mitigation details.
Mitigation direction
- Upgrade Discourse to 2.7.8, 2.8.0.beta5, or later.
- Review the GitHub advisory before rollout.
- Check vendor guidance for any deployment-specific instructions.
- Prioritize forums with sensitive user communities or private categories.
Validation and detection
- Inventory all Discourse instances and record running versions.
- Confirm production is not below 2.7.8 or 2.8.0.beta5.
- Review change management evidence for the Discourse update.
- In staging, verify unauthorized users cannot view another user's read-state metadata.
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.
CWE-200: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-37703 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
- Medium
- CVSS
- 4.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N2.81.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
4.3MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/discourse/discourse/security/advisories/GHSA-gq2h-qhg2-phf9CVE reference · x_refsource_CONFIRM
- https://github.com/discourse/discourse/commit/aed65ec16d38886d7be7209d8c02df4ffd4937a4CVE 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.
Exposure of Sensitive Information to an Unauthorized Actor
Exposure of Sensitive Information to an Unauthorized Actor represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.