In the Bouncy Castle JCE Provider version 1.55 and earlier ECDSA does not fully validate ASN.1 encoding of signature on verification. It is possible to inject extra elements in the sequence making up the signature and still have it validate, which in some cases may allow the introduction of ‘invisible’ data into a signed structure.
access.redhat.com/errata/RHSA-2018:2669
access.redhat.com/errata/RHSA-2018:2927
github.com/advisories/GHSA-qcj7-g2j5-g7r3
github.com/bcgit/bc-java
github.com/bcgit/bc-java/commit/843c2e60f67d71faf81d236f448ebbe56c62c647#diff-25c3c78db788365f36839b3f2d3016b9
lists.debian.org/debian-lts-announce/2018/07/msg00009.html
nvd.nist.gov/vuln/detail/CVE-2016-1000342
security.netapp.com/advisory/ntap-20181127-0004
usn.ubuntu.com/3727-1
www.oracle.com/security-alerts/cpuoct2020.html