Barracuda IPS Request Limit Test

The Intrusion Prevention System (IPS) defines the maximum permissible limits for various parts of an HTTP request, such as URL, headers, content, cookies, and more. In Barracuda WAF, implementing these limits helps identify malformed or oversized requests and block them before they can lead to DoS attacks, buffer overflows, or other protocol abuses. If left unnoticed, this can lead to degraded performance, service disruption, and undetected security vulnerabilities.

This test monitors incoming traffic and detects any abnormal requests that exceed the defined thresholds. It tracks overflow errors and the use of blocked HTTP methods, which in turn aids in the early detection of malicious activity. As a result, the test enables administrators to make informed decisions and fine-tune security policies, ensuring that web applications are protected from potential security threats.

Target of the test : A Barracuda WAF

Agent deploying the test : An external agent

Outputs of the test : One set of results for every Service IP:Port combination on the target firewall being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed.
Host	The IP address of the target server that is being monitored.
Data Over TCP	By default, in an IT environment, all data transmission occurs over UDP. Some environments however, may be specifically configured to offload a fraction of the data traffic – for instance, certain types of data traffic or traffic pertaining to specific components – to other protocols like TCP, so as to prevent UDP overloads. In such environments, you can instruct the eG agent to conduct the SNMP data traffic related to the monitored target over TCP (and not UDP). For this, set this flag to Yes. By default, this flag is set to No.
Timeout	Specify the duration (in seconds) within which the SNMP query executed by this test should time out in this text box. The default is 10 seconds.
SNMPPort	The port at which the monitored target exposes its SNMP MIB; the default is 161.
SNMPVersion	By default, the eG agent supports SNMP version 1. Accordingly, the default selection in the SNMPversion list is v1. However, if a different SNMP framework is in use in your environment, say SNMP v2 or v3, then select the corresponding option from this list.
Context	This parameter appears only when v3 is selected as the SNMPVERSION. An SNMP context is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context and an SNMP entity potentially has access to many contexts. A context is identified by the SNMPEngineID value of the entity hosting the management information (also called a contextEngineID) and a context name that identifies the specific context (also called a contextName). If the Username provided is associated with a context name, then the eG agent will be able to poll the MIB and collect metrics only if it is configured with the context name as well. In such cases therefore, specify the context name of the Username in the Context text box. By default, this parameter is set to none.
Username	This parameter appears only when v3 is selected as the SNMPversion. SNMP version 3 (SNMPv3) is an extensible SNMP Framework which supplements the SNMPv2 Framework, by additionally supporting message security, access control, and remote SNMP configuration capabilities. To extract performance statistics from the MIB using the highly secure SNMP v3 protocol, the eG agent has to be configured with the required access privileges – in other words, the eG agent should connect to the MIB using the credentials of a user with access permissions to be MIB. Therefore, specify the name of such a user against this parameter.
Authpass	Specify the password that corresponds to the above-mentioned Username. This parameter once again appears only if the SNMPversion selected is v3.
Confirm Password	Confirm the AuthPass by retyping it here.
AuthType	This parameter too appears only if v3 is selected as the SNMPversion. From the AuthType list box, choose the authentication algorithm using which SNMP v3 converts the specified username and password into a 32-bit format to ensure security of SNMP transactions. You can choose between the following options: MD5 - Message Digest Algorithm SHA - Secure Hash Algorithm SHA224 - Secure Hash Algorithm 224 bit SHA256 - Secure Hash Algorithm 256 bit SHA384 - Secure Hash Algorithm 384 bit SHA512 - Secure Hash Algorithm 512 bit
EncryptFlag	This flag appears only when v3 is selected as the SNMPversion. By default, the eG agent does not encrypt SNMP requests. Accordingly, the this flag is set to No by default. To ensure that SNMP requests sent by the eG agent are encrypted, select the Yes option.
EncryptType	If the EncryptFlag is set to Yes, then you will have to mention the encryption type by selecting an option from the EncryptType list. SNMP v3 supports the following encryption types: DES - Data Encryption Standard 3DES - Triple Data Encryption Standard AES - Advanced Encryption Standard AES128 - Advanced Encryption Standard 128 bit AES192 - Advanced Encryption Standard 192 bit AES256 - Advanced Encryption Standard 256 bit
EncryptPassword	Specify the encryption password here.
Confirm Password	Confirm the encryption password by retyping it here.
EngineID	This parameter appears only when v3 is selected as the SNMPVersion. Somet imes, the test may not report metrics when AES192 or AES256 is chosen as the Encryption type. To ensure that the test report metrics consistently, administrators need to set this flag to Yes. By default, this parameter is set to No.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
URL length overflow errors	Indicates the number of URL length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	URL length overflow errors refers to the requests where the URL length exceeded the configured limit. This measure could indicate usage of oversized URLs in attacks like buffer overflows or to bypass filters.
Query length overflow errors	Indicates the number of query length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	This measure value shows the number of requests with query strings exceeding acceptable lengths. Abnormally long queries can be malicious or unintentional misconfigurations.
Request length overflow errors	Indicates the number of request length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	Request length overflow errors refers to the HTTP requests that exceeded the permitted overall request size Large request bodies can lead to resource exhaustion or application crashes.
Cookie length overflow errors	Indicates the number of cookie length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	Cookie length overflow errors refer to requests that contained cookie headers exceeding the configured size limit. Long cookies may indicate tampering, session fixation, or injection attacks.
Header count overflow errors	Indicates the number of header count overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	This measure indicates the requests hat had more headers than permitted. Such patterns may indicate malicious activity or attempts to confuse or overwhelm the server.
Header length overflow errors	Indicates the number of header length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	Header length overflow errors indicates the requests with individual headers exceeding length limits. This could indicate malformed requests or evasion tactics.
Content length overflow errors	Indicates the number of content length overflow errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	Content length overflow errors refers to the requests where the content body size exceeded the configured content size.Common in POST/PUT requests and could be used in DoS attacks.
Blocked method errors	Indicates the number of blocked method errors detected on this port while processing the requests for this service IP during the last measurement period.	Number	Blocked method errors gives the number of requests using HTTP methods that are not permitted by security policy.This includes TRACE, CONNECT, etc.This measure helps to protect from method-based exploits.