Bug ID 571482: Unbalanced double-quotes may merge lines upon config save-then-load

Last Modified: Sep 14, 2023

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

Known Affected Versions:
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, 12.1.0, 12.1.1, 12.1.2, 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

Opened: Feb 02, 2016

Severity: 3-Major

Symptoms

Unbalanced double-quotes used in the configuration will cause load failure, or will merge subsequent configuration lines until a balancing double-quote character is found. For example, an improper expression may be used to configure a monitor 'recv' value that results in an unbalanced (odd number) of double-quote characters, such as "R\\"eceive" (note three double-quote characters, resulting in an unbalanced string). The string is considered unbalanced with an odd number of double-quote characters, regardless of escaping (such as double- or triple-backslash escaping).

Impact

The configuration will fail to load, as it is improperly formed. In some cases the configuration may successfully load, but the unbalanced string will cause newline(s) to be implicitly escaped until a balancing double-quote is found; this will merge subsequent lines to the unbalanced line, resulting in the consumed lines to not be considered as configuration values, but as the merged continuation of the unbalanced line.

Conditions

An odd count of double-quotes are used for a configuration value, resulting in an unbalanced string. For example, configuring a monitor 'recv' value as "R\\"eceive" results in an unbalanced string (notice three double-quotes, an odd number).

Workaround

Modify configuration values that use double-quotes to be balanced (i.e., configuration items should have an even-number of double-quoted characters, even if they are escaped).

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips