CVE-2017-2773
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn issue was discovered in Pivotal PCF Elastic Runtime 1.6.x versions prior to 1.6.60, 1.7.x versions prior to 1.7.41, 1.8.x versions prior to 1.8.23, and 1.9.x versions prior to 1.9.1. Incomplete validation logic in JSON Web Token (JWT) libraries can allow unprivileged attackers to impersonate other users in multiple components included in PCF Elastic Runtime, aka an "Unauthenticated JWT signing algorithm in multiple components" issue.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceVulnerability in Pivotal PCF Elastic Runtime's JWT library validation logic allows attackers to bypass signature verification by manipulating the JWT algorithm header (e.g., using 'none' algorithm or algorithm confusion). This enables unauthenticated attackers to forge tokens and impersonate any user across multiple PCF components.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 1.6.0= 1.6.1= 1.6.2= 1.6.3= 1.6.4= 1.6.5= 1.6.6= 1.6.7= 1.6.8= 1.6.9= 1.6.10= 1.6.11CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Determine installed Elastic Runtime versionLog into the Pivotal Ops Manager dashboard, navigate to the Elastic Runtime tile, and check the Product Version field. Alternatively, use the cf CLI command: cf curl /v2/buildpacks | grep elastic-runtimeAffected if The version is between 1.6.0 and 1.6.11 inclusive (e.g., 1.6.0, 1.6.5, 1.6.11)
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Identify UAA component versionThe UAA (User Account and Authentication) server handles JWT token validation in PCF. Check the UAA version via the Ops Manager stemcell or by querying the UAA endpoint /login with 'cf login' and reviewing token responses.Affected if UAA version corresponds to an unpatched Elastic Runtime in the 1.6.x range
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Verify JWT token handling is in useReview your PCF environment to confirm applications or services rely on JWT tokens for authentication. Check if the cf CLI or any bound services utilize UAA-issued tokens by inspecting traffic or reviewing application manifests.Affected if JWT tokens from PCF UAA are actively used for authentication in the environment
The environment is affected if Elastic Runtime version is 1.6.0 through 1.6.11 and the system relies on JWT-based authentication via the UAA component.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Elastic Runtime to patched versions: 1.6.60+, 1.7.41+, 1.8.23+, or 1.9.1+. These versions implement proper JWT validation that rejects tokens with unexpected or missing algorithms.
Upgrade to Elastic Runtime 1.6.60 (for 1.6.x users), 1.7.41 (for 1.7.x users), 1.8.23 (for 1.8.x users), or 1.9.1 (for 1.9.x users)
- 1. Identify the current PCF Elastic Runtime version by accessing the Ops Manager UI and checking the Elastic Runtime product tile version.
- 2. Determine the appropriate upgrade path based on current version: if on 1.6.x, upgrade to 1.6.60; if on 1.7.x, upgrade to 1.7.41; if on 1.8.x, upgrade to 1.8.23; if on 1.9.x, upgrade to 1.9.1.
- 3. Review the Pivotal Cloud Foundry upgrade documentation for your current version to ensure compatibility with the target version.
- 4. Create a backup of the current PCF environment, including all tile configurations and any custom manifests.
- 5. In Ops Manager, navigate to the Elastic Runtime tile and update the product to the chosen fixed version.
- 6. Run 'Apply Changes' in Ops Manager to deploy the patched Elastic Runtime.
- 7. After upgrade completes, verify JWT token validation is working by testing authentication flows across affected components (UAA, Router, and other components that use JWT).
- 8. Confirm that JWT tokens with 'none' algorithm or tampered signatures are now properly rejected.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-2773 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2017-2773 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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