Bug ID 758631: ec_point_formats extension might be included in the server hello even if not specified in the client hello

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP LTM(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, 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, 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, 14.1.0, 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, 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, 14.1.2.5, 14.0.1.1, 13.1.3.5, 12.1.5

Opened: Feb 13, 2019

Severity: 3-Major

Symptoms

RFC 5246 states that if an extension does not exist in the client hello, it must not exist in the server hello. When an EC cipher suite is selected, the server might send the ec_point_formats extension, even if none exists in the client hello.

Impact

Some clients abort the connection in this case.

Conditions

-- An EC cipher suite is selected. -- The client does not send an ec_point_formats extension.

Workaround

There is no workaround other than not configuring any EC cipher suites.

Fix Information

With this change, the server does not send an unsolicited ec_point_formats extension.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips