CVE-2023-33202 is a medium-severity (CVSS 5.5) Uncontrolled Resource Consumption vulnerability in org.bouncycastle:bcprov-ext-jdk16. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.bouncycastle:bcprov-ext-jdk16 — see the affected versions and patch details below.
Bouncy Castle Denial of Service (DoS)
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-2023-33202.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-33202 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
org.bouncycastle:bcprov-ext-jdk16☕org.bouncycastle:bcprov-jdk14☕org.bouncycastle:bcprov-jdk15☕org.bouncycastle:bcprov-jdk15to18☕org.bouncycastle:bcprov-jdk16☕org.bouncycastle:bcprov-jdk15on☕org.bouncycastle:bcpkix-jdk18on☕org.bouncycastle:bcprov-ext-jdk15on+1 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Bouncy Castle for Java before 1.73 contains a potential Denial of Service (DoS) issue within the Bouncy Castle org.bouncycastle.openssl.PEMParser class. This class parses OpenSSL PEM encoded streams containing X.509 certificates, PKCS8 encoded keys, and PKCS7 objects. Parsing a file that has crafted ASN.1 data through the PEMParser causes an OutOfMemoryError, which can enable a denial of service attack. (For users of the FIPS Java API: BC-FJA 1.0.2.3 and earlier are affected; BC-FJA 1.0.2.4 is fixed.)
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.bouncycastle:bcprov-ext-jdk16 | all versions | 1.73org.bouncycastle:bcprov-ext-jdk16:1.73 |
| ☕Maven | org.bouncycastle:bcprov-jdk14 | all versions | 1.73org.bouncycastle:bcprov-jdk14:1.73 |
| ☕Maven | org.bouncycastle:bcprov-jdk15 | all versions | 1.73org.bouncycastle:bcprov-jdk15:1.73 |
| ☕Maven | org.bouncycastle:bcprov-jdk15to18 | all versions | 1.73org.bouncycastle:bcprov-jdk15to18:1.73 |
| ☕Maven | org.bouncycastle:bcprov-jdk16 | all versions | 1.73org.bouncycastle:bcprov-jdk16:1.73 |
| ☕Maven | org.bouncycastle:bcprov-jdk15on | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.bouncycastle:bcprov-ext-jdk16, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.bouncycastle:bcprov-ext-jdk16 to 1.73 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-33202 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-33202 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-33202. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2023-33202 in your dependencies?
O3 Security finds CVE-2023-33202 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.