CVE-2018-5382: 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 Cast...

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.

Metrics

CVSS 3.1

4.4/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS Probability

0.26%

17.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Bouncycastle	Bc-Java	<= 1.49
Redhat	Satellite	6.4
Redhat	Satellite Capsule	6.4

References

http://www.securityfocus.com/bid/103453Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2018:2927Third Party Advisory
https://www.bouncycastle.org/releasenotes.htmlRelease Notes, Vendor Advisory
https://www.kb.cert.org/vuls/id/306792Third Party Advisory, US Government Resource
https://www.oracle.com/security-alerts/cpuoct2020.htmlThird Party Advisory
http://www.securityfocus.com/bid/103453Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2018:2927Third Party Advisory
https://www.bouncycastle.org/releasenotes.htmlRelease Notes, Vendor Advisory
https://www.kb.cert.org/vuls/id/306792Third Party Advisory, US Government Resource
https://www.oracle.com/security-alerts/cpuoct2020.htmlThird Party Advisory

Timeline

Published: Apr 16, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-5382?

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.

How severe is CVE-2018-5382?

CVE-2018-5382 has a CVSS score of 4.4/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2018-5382?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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