Bug ID 530102: Illegal meta characters on XML tags -

Last Modified: Sep 13, 2023

Affected Product(s):
BIG-IP ASM, Install/Upgrade(all modules)

Known Affected Versions:
11.5.0, 11.5.1, 11.5.2, 11.5.3, 11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.1.0

Opened: Jun 26, 2015

Severity: 3-Major

Symptoms

After upgrading from 11.4.1 to 11.6.0, 11.6.1 or 12.0.0, you see a lot of "Illegal meta character in value" false positives on your XML content. The flagged character are valid within XML (<, >, /, :, etc.) and the affected URLs are associated with legitimate XML profiles via header-based content profiles. From the security event report, one can see that the invalid characters are for the global UNNAMED wildcard parameter and that the request is a multipart POST.

Impact

False positive violations could happen on the parameter enforcement (as it's not a parameter content but XML).

Conditions

XML profile is assigned to the wildcard URL and having Header-Based Content profile.

Workaround

N/A

Fix Information

Fixed a scenario when an XML profile is configured on the URL to not parse multipart root XML as form-data parameter, but only as XML.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips