Security readout for executives and security teams
Plain-English summary
This issue can let an attacker disrupt Cloud Foundry availability by causing Gorouter instances to be removed from an NGINX backend pool. The risk is specific to Cloud Foundry deployments using NGINX reverse proxies in front of Gorouter and affected Routing versions before 0.204.0.
Executive priority
Treat this as a high-priority availability risk for affected Cloud Foundry platforms. Prioritize confirmation of NGINX-fronted Gorouter exposure and upgrade planning, especially for internet-facing foundations or business-critical application platforms.
Technical view
Cloud Foundry Routing/Gorouter before 0.204.0 may mishandle specially crafted HTTP requests when deployed behind NGINX reverse proxies. The reported impact is denial of service through Gorouters being dropped from NGINX backend rotation. The CVE description says unauthenticated attack, while the supplied CVSS vector lists PR:L.
Likely exposure
Exposure is likely limited to Cloud Foundry environments with NGINX reverse proxies placed in front of Gorouter and Routing versions prior to 0.204.0.
Exploitation context
The supplied sources do not show CISA KEV listing or confirmed active exploitation. The reported attack is network-reachable and availability-focused, but exploit details should not be assumed beyond the vendor and CVE descriptions.
Researcher notes
Focus validation on topology and versioning, not generic Cloud Foundry presence. The affected condition requires NGINX in front of Gorouter and Routing before 0.204.0. Evidence provided does not include public exploit confirmation, weaponized details, or additional mitigations beyond the fixed version signal.
Mitigation direction
- Upgrade Cloud Foundry Routing/Gorouter to version 0.204.0 or later.
- Review the Cloud Foundry advisory for deployment-specific upgrade guidance.
- Confirm CF Deployment consumes a fixed Routing release.
- Monitor NGINX backend pool health for unexpected Gorouter removals.
- Apply vendor-supported configuration workarounds only if Cloud Foundry documents them.
Validation and detection
- Inventory Cloud Foundry Routing and Gorouter versions across foundations.
- Confirm whether NGINX reverse proxies sit in front of Gorouter.
- Check deployment manifests for CF Deployment Routing release versions.
- Review NGINX logs and upstream health events for unexplained Gorouter drops.
- Validate availability behavior after upgrading in a staging environment.
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
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CWE-404: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-5416 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
- High
- CVSS
- 7.7 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
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:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H3.14Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.7HighVector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.cloudfoundry.org/blog/cve-2020-5416CVE reference · x_refsource_CONFIRM
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.
Improper Resource Shutdown or Release
Improper Resource Shutdown or Release represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.