Unbound before 1.9.5 allows an out-of-bounds write via a compressed name in rdata_copy. Reference: https://ostif.org/our-audit-of-unbound-dns-by-x41-d-sec-full-results/
Upstream patch: https://github.com/NLnetLabs/unbound/commit/6c3a0b54ed8ace93d5b5ca7b8078dc87e75cd640
Statement: According to the original report there are checks happening before the affected function that make this not exploitable. For these reasons its Impact is Moderate.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:1853 https://access.redhat.com/errata/RHSA-2021:1853
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2019-25042
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Extended Update Support Via RHSA-2022:0632 https://access.redhat.com/errata/RHSA-2022:0632