# CVE-2018-5382: Bouncy Castle BKS-V1 keystore files vulnerable to trivial hash collisions

> Attackers can compromise BKS keystore integrity due to weak 16-bit HMAC, allowing unauthorized modification of stored keys.

- **Severity:** Medium 4.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Apr 2018
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2018-5382, GHSA-8477-3v39-ggpm

## What is CVE-2018-5382?

CVE-2018-5382 is a medium-severity vulnerability in Bouncycastle Bc-Java, published on 16 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The default BKS keystore use an HMAC that is only 16 bits long, which can allow an attacker to compromise the integrity of a BKS keystore. Bouncy Castle release 1.47 changes the BKS format to a format which uses a 160 bit HMAC instead. This applies to any BKS keystore generated prior to BC 1.47. For situations where people need to create the files for legacy reasons a specific keystore type "BKS-V1" was introduced in 1.49. It should be noted that the use of "BKS-V1" is discouraged by the library authors and should only be used where it is otherwise safe to do so, as in where the use of a 16 bit checksum for the file integrity check is not going to cause a security issue in itself.

Weakness: CWE-354 (Improper Validation of Integrity Check Value), CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2018-5382?

2 open source packages ship an affected version, including org.bouncycastle:bcprov-jdk15on. It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.bouncycastle:bcprov-jdk15on` | Maven | All versions | 1.50 |
| `org.bouncycastle:bcprov-jdk15on` | Maven | All versions | 1.50 |

Products: Bouncycastle Bc-Java, Redhat Satellite, Redhat Satellite Capsule.

## How do I fix CVE-2018-5382?

Upgrade org.bouncycastle:bcprov-jdk15on to 1.50 or later.

## Is CVE-2018-5382 being exploited?

There is no known exploitation of CVE-2018-5382 in the wild and no public exploit code.

## Other vulnerabilities in Bouncycastle Bc-Java

- [CVE-2007-6721](https://insights.sbomify.com/CVE-2007-6721/): Legion of the Bouncy Castle Java Cryptography API Bleichenbacher Oracle Vulnerability (critical 10.0)
- [CVE-2018-1000613](https://insights.sbomify.com/CVE-2018-1000613/): Deserialization of Untrusted Data in Bouncy castle (critical 9.8)
- [CVE-2026-58062](https://insights.sbomify.com/CVE-2026-58062/): Stapled OCSP response accepted without binding to the checked certificate (critical 9.3)
- [CVE-2026-59638](https://insights.sbomify.com/CVE-2026-59638/): JSSE hostname verifier CN-fallback enabled by default despite documented opt-in (critical 9.3)
- [CVE-2026-59650](https://insights.sbomify.com/CVE-2026-59650/): MTI/A0 DH agreement exponentiates unvalidated peer value (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-5382 and fix it if it is affected.

What it is: CVE-2018-5382 is a medium-severity vulnerability in Bouncycastle Bc-Java, published on 16 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-5382 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.bouncycastle:bcprov-jdk15on (Maven): affected all versions; fixed in 1.50
- org.bouncycastle:bcprov-jdk15on (Maven): affected all versions; fixed in 1.50

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-5382/ (Markdown: https://insights.sbomify.com/CVE-2018-5382/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-5382
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-5382
- OSV: https://osv.dev/vulnerability/CVE-2018-5382

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-5382/
Summaries are generated and may contain mistakes; the official description above is the record.