A timing attacker against ECDSA signature generation is able to obtain information from the secret nonce measuring the time an ECDSA signature generation takes. Current NSS code path has a countermeasure to prevent this know attack since 2011. However it was found that said countermeasure could be completely bypassed. Different flaw from CVE-2020-6829.
Acknowledgments: Name: the Mozilla Project Upstream: Cesar Pereida Garcia and the Network and Information Security Group (NISEC)
Upstream patch: https://hg.mozilla.org/projects/nss/rev/aeb2e583ee957a699d949009c7ba37af76515c20 Upstream bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1631573
External References: https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/NSS_3.55_release_notes
Statement: This is a side channel attack which can used to exact pirate keys when ECDSA signatures are being generated. This attack is only feasible when the attacker is local to the machine or in certain cross-VM scenarios where the signature is being generated. Attacks over the network or via the internet are not feasible.
Mitigation: This is a side channel attack which can used to exact pirate keys when ECDSA signatures are being generated. This attack is only feasible when the attacker is local to the machine or in certain cross-VM scenarios where the signature is being generated. Attacks over the network or via the internet are not feasible.
Created nss tracking bugs for this issue: Affects: fedora-all [bug 1862393]
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:4076 https://access.redhat.com/errata/RHSA-2020:4076
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-2020-12401
How come this has been addressed for RHEL 7 but not RHEL 8 ? The CVE page still indicates RHEL 8 is 'affected.
The CVE page is now updated, showing that nss in RHEL-8 was fixed via RHSA-2021:0538.