Bug ID 767989: DNSSEC RRSIG Inception Offset

Last Modified: Sep 14, 2023

Affected Product(s):
BIG-IP DNS(all modules)

Known Affected Versions:
12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1, 14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 14.1.5.4, 14.1.5.6, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4

Fixed In:
15.1.0

Opened: Apr 03, 2019

Severity: 4-Minor

Symptoms

When a DNSSEC key is used to generate an RRSIG record for the first time, the inception time of the record is set to the current BIG-IP system time. If the system that validates that signed DNS response has a clock skew towards the past relative to the BIG-IP system, then that system will see the RRSIG as if it was generated for a future timestamp and is not yet valid.

Impact

This may cause validation of a DNSSEC response to fail if the validator finds that there are no valid RRSIG records signing the response.

Conditions

-- DNSSEC is used to sign responses for a particular DNS zone. -- The clock of the validating resolver is running behind the clock of the BIG-IP system.

Workaround

None.

Fix Information

This fix causes all generated RRSIG records to have their inception time backdated by exactly 1 hour.

Behavior Change

The inception time of all RRSIG records is backdated by exactly 1 hour. The time that the RRSIG record is generated and the time it expires is unchanged. The RRSIG inception time will appear as 1 hour before the RRSIG was generated.

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips