PMD Designer's release key passphrase (GPG) available on Maven Central in cleartext

Summary

While rebuilding PMD Designer for Reproducible Builds and digging into issues, I found out that passphrase for gpg.keyname=0xD0BF1D737C9A1C22 is included in jar published to Maven Central.

Details

See https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/net/sourceforge/pmd/pmd-designer/README.md

I removed 2 lines from https://github.com/jvm-repo-rebuild/reproducible-central/blob/master/content/net/sourceforge/pmd/pmd-designer/pmd-designer-7.0.0.diffoscope but real content is:

├── net/sourceforge/pmd/util/fxdesigner/designer.properties
│ @@ -1,14 +1,12 @@
│  #Properties
│  checkstyle.plugin.version=3.3.1
│  checkstyle.version=10.14.0
│ -gpg.keyname=0xD0BF1D737C9A1C22
│ -gpg.passphrase=evicx0nuPfvSVhVyeXpw
│  jar.plugin.version=3.3.0
│ -java.version=11.0.22
│ +java.version=11.0.25
│  javadoc.plugin.version=3.6.3
│  jflex-output=/home/runner/work/pmd-designer/pmd-designer/target/generated-sources/jflex
│  junit5.version=5.8.2
│  kotest.version=5.5.5
│  kotlin.version=1.7.20
│  local.lib.repo=/home/runner/work/pmd-designer/pmd-designer/lib/mvn-repo
│  openjfx.scope=provided

PoC

./rebuild.sh content/net/sourceforge/pmd/pmd-designer/pmd-designer-7.0.0.buildspec

Impact

After further analysis, the passphrase of the following two keys have been compromised:

1. 94A5 2756 9CAF 7A47 AFCA BDE4 86D3 7ECA 8C2E 4C5B: PMD Designer (Release Signing Key) releases@pmd-code.org This key has been used since 2019 with the release of net.sourceforge.pmd:pmd-ui:6.14.0. The following versions are signed with the same key: 6.16.0, 6.17.0, 6.19.0.
2. EBB2 41A5 45CB 17C8 7FAC B2EB D0BF 1D73 7C9A 1C22: PMD Release Signing Key releases@pmd-code.org This key has been used since 2020 with the release of net.sourceforge.pmd:pmd-ui:6.21.0 and all the other modules of PMD such as net.sourceforge.pmd:pmd-core:6.21.0.
   This key has also been used for PMD 7, for the designer, e.g. net.sourceforge.pmd:pmd-designer:7.0.0 and net.sourceforge.pmd:pmd-core:7.0.0. The versions between 6.21.0 and 7.9.0 are signed with this key.
   Additionally the key has been used to sign the last release of PMD Eclipse Plugin 7.9.0.v20241227-1626-r.

The keys have been used exclusively for signing artifacts that we published to Maven Central under group id net.sourceforge.pmd and once for our pmd-eclipse-plugin. The private key itself is not known to have been compromised itself, but given its passphrase is, it must also be considered potentially compromised.

As a mitigation, both compromised keys have been revoked so that no future use of the keys are possible. For future releases of PMD, PMD Designer and PMD Eclipse Plugin we use a new release signing key: 2EFA 55D0 785C 31F9 56F2 F87E A0B5 CA1A 4E08 6838 (PMD Release Signing Key releases@pmd-code.org).

Note, that the published artifacts in Maven Central under the group id net.sourceforge.pmd are not compromised and the signatures are valid. No other past usages of the private key is known to the project and no future use is possible due to the revocation. If anybody finds a past abuse of the private key, please share with us.

Note, the module net.sourceforge.pmd:pmd-ui has been renamed to net.sourceforge.pmd:pmd-designer since PMD 7, so there won't be a fixed version for pmd-ui.

Fixes

• Reworked build script in PMD Designer to not include all system properties
  • https://github.com/pmd/pmd-designer/commit/1548f5f27ba2981b890827fecbd0612fa70a0362
  • https://github.com/pmd/pmd-designer/commit/e87a45312753ec46b3e5576c6f6ac1f7de2f5891

References

• GHSA-88m4-h43f-wx84
• CVE-2025-23215
• reproducible-central