CVE-2020-28052 is a high-severity (CVSS 8.1) vulnerability in org.bouncycastle:bcprov-jdk15to18. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.bouncycastle:bcprov-jdk15to18 — see the affected versions and patch details below.
Logic error in Legion of the Bouncy Castle BC Java
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-2020-28052 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 378,567 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-jdk15to18☕org.bouncycastle:bcprov-jdk15☕org.bouncycastle:bcprov-jdk15on☕org.bouncycastle:bcprov-ext-jdk15on☕org.bouncycastle:bcprov-jdk14☕org.bouncycastle:bcprov-jdk16☕org.bouncycastle:bcprov-ext-jdk16Real-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
An issue was discovered in Legion of the Bouncy Castle BC Java 1.65 and 1.66. The OpenBSDBCrypt.checkPassword utility method compared incorrect data when checking the password, allowing incorrect passwords to indicate they were matching with previously hashed ones that were different.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.bouncycastle:bcprov-jdk15to18 | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-jdk15to18:1.67 |
| ☕Maven | org.bouncycastle:bcprov-jdk15 | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-jdk15:1.67 |
| ☕Maven | org.bouncycastle:bcprov-jdk15on | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-jdk15on:1.67 |
| ☕Maven | org.bouncycastle:bcprov-ext-jdk15on | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-ext-jdk15on:1.67 |
| ☕Maven | org.bouncycastle:bcprov-jdk14 | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-jdk14:1.67 |
| ☕Maven | org.bouncycastle:bcprov-jdk16 | ≥ 1.65&&< 1.67 | 1.67org.bouncycastle:bcprov-jdk16:1.67 |
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-jdk15to18, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.bouncycastle:bcprov-jdk15to18 to 1.67 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-28052 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-2020-28052 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-28052. 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.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat EAP-XP 2.0.0 via EAP 7.3.x base | bouncycastle | RHSA-2021:2755 |
| Red Hat EAP-XP via EAP 7.3.x base | bouncycastle | RHSA-2021:2210 |
| Red Hat Fuse 7.8.1 | karaf | RHSA-2021:1401 |
| Red Hat Fuse 7.9 | bouncycastle | RHSA-2021:3140 |
| Red Hat Integration | see advisory | RHSA-2021:3205 |
| Red Hat Integration Camel Quarkus 2 | see advisory | RHSA-2021:4767 |
| Red Hat JBoss Enterprise Application Platform 7 | bcprov-jdk15 | RHSA-2021:0885 |
| Red Hat JBoss Enterprise Application Platform 7.1 EUS for RHEL 7 | eap7-bouncycastle-0:1.68.0-1.redhat_00005.1.ep7.el7 | RHSA-2024:10208 |
Frequently Asked Questions
Is CVE-2020-28052 in your dependencies?
O3 Security finds CVE-2020-28052 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.