CVE-2022-34862 - Loop with Unreachable Exit Condition ('Infinite Loop')

Severity

75%

Complexity

39%

Confidentiality

60%

In BIG-IP Versions 16.1.x before 16.1.3.1, 15.1.x before 15.1.6.1, 14.1.x before 14.1.5, and all versions of 13.1.x, when an LTM virtual server is configured to perform normalization, undisclosed requests can cause the Traffic Management Microkernel (TMM) to terminate. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS 3.1 Base Score 7.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Demo Examples

Loop with Unreachable Exit Condition ('Infinite Loop')

CWE-835

In the following code the method processMessagesFromServer attempts to establish a connection to a server and read and process messages from the server. The method uses a do/while loop to continue trying to establish the connection to the server when an attempt fails.


               
}
...// create socket to connect to server
}// establish connection to server// if connected then read and process messages from server
...// read and process messages
// keep trying to establish connection to the server// close socket and return success or failure

However, this will create an infinite loop if the server does not respond. This infinite loop will consume system resources and can be used to create a denial of service attack. To resolve this a counter should be used to limit the number of attempts to establish a connection to the server, as in the following code.


               
}
...// initialize number of attempts counter
}// establish connection to server// increment counter// if connected then read and process messages from server
...// read and process messages
// keep trying to establish connection to the server// up to a maximum number of attempts// close socket and return success or failure

Loop with Unreachable Exit Condition ('Infinite Loop')

CWE-835

For this example the method isReorderNeeded as part of a bookstore application that determines if a particular book needs to be reordered based on the current inventory count and the rate at which the book is being sold.


               
}
return isReorder;// get inventory count for book// find number of days until inventory count reaches minimum
days++;
// if number of days within reorder timeframe// set reorder return boolean to true
isReorder = true;

However, the while loop will become an infinite loop if the rateSold input parameter has a value of zero since the inventoryCount will never fall below the minimumCount. In this case the input parameter should be validated to ensure that a value of zero does not cause an infinite loop,as in the following code.


               
}
...// validate rateSold variable
return isReorder;

Overview

Type

F5

First reported 2 years ago

2022-08-04 18:15:00

Last updated 2 years ago

2022-08-10 18:16:00

Affected Software

F5 Big-IP Analytics

F5 Big-IP Link Controller

F5 Networks Big-IP Local Traffic Manager (LTM)

F5 Big-IP Policy Enforcement Manager (PEM)

F5 Big-IP Access Policy Manager (APM)

F5 Big-IP Advanced Firewall Manager (AFM)

F5 Big-IP Application Acceleration Manager (AAM)

F5 Big-IP Application Security Manager (ASM)

F5 Big-IP Domain Name System (DNS)

F5 Big-IP Fraud Protection Service (FPS)

F5 Big-IP Global Traffic Manager (GTM)

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