Security Resilience

CVE-2023-47121

SSRF in Discourse ≤ 3.1.3

Published
10 November 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 3.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:N/A:N
EPSS Score 0.0069 52th percentile
Risk Priority 31 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-47121 is a low-severity SSRF (CWE-918) vulnerability in Discourse Discourse. Its CVSS base score is 3.4 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked in the top 48% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Discourse is an open source platform for community discussion. Prior to version 3.1.3 of the `stable` branch and version 3.2.0.beta3 of the `beta` and `tests-passed` branches, the embedding feature is susceptible to server side request forgery. The issue is patched…

more

in version 3.1.3 of the `stable` branch and version 3.2.0.beta3 of the `beta` and `tests-passed` branches. As a workaround, disable the Embedding feature.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
T1021.001 Remote Desktop Protocol Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.002 SMB/Windows Admin Shares Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.004 SSH Lateral Movement
Adversaries may use [Valid Accounts](https://attack.
T1021.007 Cloud Services Lateral Movement
Adversaries may log into accessible cloud services within a compromised environment using [Valid Accounts](https://attack.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-68662Same product: Discourse Discourse
CVE-2023-28112Same product: Discourse Discourse
CVE-2024-37157Same product: Discourse Discourse
CVE-2023-28111Same product: Discourse Discourse
CVE-2026-33185Same product: Discourse Discourse
CVE-2025-58054Same product: Discourse Discourse
CVE-2026-27166Same product: Discourse Discourse
CVE-2023-37467Same product: Discourse Discourse
CVE-2026-27934Same product: Discourse Discourse
CVE-2026-27935Same product: Discourse Discourse

Affected Assets

discourse
discourse
3.2.0 · ≤ 3.1.3 · ≤ 3.2.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-918

Penetration testing attempts server-side requests to internal resources, identifying SSRF weaknesses for remediation.

addresses: CWE-918

Outbound connections to external resources can be monitored and limited at the boundary, reducing SSRF impact.

addresses: CWE-918

Validates server-side URLs and resource references to block SSRF attempts.

addresses: CWE-918

Detects server-side request forgery through monitoring of unexpected outbound connections.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

DE.CM-09 partial match
blocks

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
blocks

Network segmentation and egress controls can limit the damage from successful SSRF requests.

PR.PS-06 partial match
blocks

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

removes
removes
removes
removes

References