Bug ID 546747: SSL connections may fail with a handshake failure when the ClientHello is sent in multiple packets

Last Modified: Apr 28, 2025

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

Known Affected Versions:
11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4

Fixed In:
12.1.0, 11.6.1, 11.5.4 HF2

Opened: Sep 18, 2015

Severity: 4-Minor

Related Article: K72042050

Symptoms

Sometimes BIG-IP system responds with a fatal-handshake alert and closes the SSL session for a new connection when a ClientHello record is split between two or more packets. If SSL debug logging is enabled, the system logs an error such as the following: 01260009:7: Connection error: ssl_hs_rxhello:6210: ClientHello contains extra data (47). Note: For information on SSL debug logging, see SOL15292: Troubleshooting SSL/TLS handshake failures at https://support.f5.com/kb/en-us/solutions/public/15000/200/sol15292.html.

Impact

SSL connections fail to complete with a handshake failure.

Conditions

This occurs when a SSL ClientHello record is split across multiple TCP segments, and the last segment is relatively small.

Workaround

No workaround.

Fix Information

SSL handshakes no longer fails to complete when the ClientHello is split across multiple TCP segments, and the last segment is relatively small.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips