CVE-2025-23206
Fix: aws/aws-cdk@3e4f377CVE-2025-23206 is a CWE-347 vulnerability in aws-cdk-lib. O3 Security confirms whether CVE-2025-23206 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
IAM OIDC custom resource allows connection to unauthorized OIDC provider in aws-cdk
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-23206.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
aws-cdk-libnpmDescription
The AWS Cloud Development Kit (AWS CDK) is an open-source software development framework to define cloud infrastructure in code and provision it through AWS CloudFormation. Users who use IAM OIDC custom resource provider package will download CA Thumbprints as part of the custom resource workflow. However, the current tls.connect method will always set rejectUnauthorized: false which is a potential security concern. CDK should follow the best practice and set rejectUnauthorized: true. However, this could be a breaking change for existing CDK applications and we should fix this with a feature flag. Note that this is marked as low severity Security advisory because the issuer url is provided by CDK users who define the CDK application. If they insist on connecting to a unauthorized OIDC provider, CDK should not disallow this. Additionally, the code block is run in a Lambda environment which mitigate the MITM attack. The patch is in progress. To mitigate, upgrade to CDK v2.177.0 (Expected release date 2025-02-22). Once upgraded, users should make sure the feature flag '@aws-cdk/aws-iam:oidcRejectUnauthorizedConnections' is set to true in cdk.context.json or cdk.json. There are no known workarounds for this vulnerability.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | aws-cdk-lib | all versions | 2.177.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aws-cdk-lib. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update aws-cdk-lib to 2.177.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-23206 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-23206 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-23206. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-23206 in your dependencies?
O3 detects CVE-2025-23206 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.