Bug ID 525478: Requests for deflate encoding of gzip documents may crash TMM

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP AAM, WAM(all modules)

Known Affected Versions:
11.2.1, 11.3.0, 11.4.0, 11.4.1, 11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.6.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.0.0, 11.6.1, 11.5.4

Opened: May 28, 2015

Severity: 3-Major

Related Article: K80413728

Symptoms

When searching for documents in the gzip cache, if a document has been cached with gzip encoding but a non-deflate compression method (i.e., CM != 0x08) and the client has requested deflate compression, TMM may crash.

Impact

Traffic disrupted while tmm restarts.

Conditions

-- WAM/AAM enabled on VIP. -- HTTP compression enabled on VIP. -- Document served with gzip encoding and non-deflate compression. -- Document has entered the gzip cache. -- Client HTTP request specifies deflate encoding.

Workaround

Ensure that only the deflate method is used in gzip-compressed documents that will be cached by WAM/AAM. With most web servers this is the default behavior and cannot be changed. Alternatively, remove the 'Accept-Encoding: deflate' header using an iRule so that no clients can request deflate encoding.

Fix Information

Correctly handles requests for deflate compression of cached gzip documents with non-deflate compression methods.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips