CVE-2024-3400: PAN-OS Command Injection Vulnerability in GlobalProtect Gateway. Learn More

CVE-2024-3400: PAN-OS Command Injection Vulnerability in GlobalProtect Gateway. Learn More

Services
Capture
Managed Detection & Response

Eliminate active threats with 24/7 threat detection, investigation, and response.

twi-managed-portal-color
Co-Managed SOC (SIEM)

Maximize your SIEM investment, stop alert fatigue, and enhance your team with hybrid security operations support.

twi-briefcase-color-svg
Advisory & Diagnostics

Advance your cybersecurity program and get expert guidance where you need it most.

tw-laptop-data
Penetration Testing

Test your physical locations and IT infrastructure to shore up weaknesses before exploitation.

twi-database-color-svg
Database Security

Prevent unauthorized access and exceed compliance requirements.

twi-email-color-svg
Email Security

Stop email threats others miss and secure your organization against the #1 ransomware attack vector.

tw-officer
Digital Forensics & Incident Response

Prepare for the inevitable with 24/7 global breach response in-region and available on-site.

tw-network
Firewall & Technology Management

Mitigate risk of a cyberattack with 24/7 incident and health monitoring and the latest threat intelligence.

Solutions
BY TOPIC
Offensive Security
Solutions to maximize your security ROI
Microsoft Exchange Server Attacks
Stay protected against emerging threats
Rapidly Secure New Environments
Security for rapid response situations
Securing the Cloud
Safely navigate and stay protected
Securing the IoT Landscape
Test, monitor and secure network objects
Why Trustwave
About Us
Awards and Accolades
Trustwave SpiderLabs Team
Trustwave Fusion Security Operations Platform
Trustwave Security Colony
Partners
Technology Alliance Partners
Key alliances who align and support our ecosystem of security offerings
Trustwave PartnerOne Program
Join forces with Trustwave to protect against the most advance cybersecurity threats
SpiderLabs Blog

Web Services Security

NIST has released a new guide on securing Web Services. It is a pretty good read for anyone who is planning to run WS, specifically Appendix A which lists Common WS Attack categories such as:

  • Reconnaissance Attacks
  • Privilege Escalation Attacks
  • Attacks on Confidentiality
  • Attacks on Integrity
  • Denial of Service Attacks
  • Command Injection
  • Malicious Code Attacks

Protecting Web Services with ModSecurity

If you compile ModSecurity 2.x with XML support (with libxml2) and activate the libxml2.so file in httpd.conf, you can gain some protection for your WS traffic. While ModSecurity can not prevent every WS attack category listed above, it can certainly help to prevent a large number of the common HTTP attacks that now simply riding in the XML payloads.

XML Support in the Core Rules

Version 1.4 build 2 of the Core Rules introduced support for inspecting the the XML payloads of Web Services transactions. You can identify this by the inclusion of the XML:/* data in the variable listing. An example rule is listed below:

# Email Injection
SecRule REQUEST_FILENAME|ARGS|ARGS_NAMES|REQUEST_HEADERS|XML:/* "[\n\r]\s*(?:to|bcc|cc)\s*:.*?\@" \
"t:none,t:lowercase,t:urlDecode,capture,ctl:auditLogParts=+E,log,auditlog,msg:'Email Injection Attack. Matched signature <%{TX.0}>',,id:'950019',severity:'2'"

Since the Core Rules offers generic detection and does not tie specific attack payloads to specific parameters, the XML:/* variable is somewhat similar to the REQUEST_BODY payload in that ModSecurity will treat it as one large piece of data. This results in ModSecurity searching the entire XML payload looking for rule matches. For those ModSecurity users who are familiar with the 1.9.x branch, this is similar to the SecFilter rule processing where it performs a wider search for attacks as it does not know exactly where the input vectors are located. The side-effect is that there may be a performance hit if you WS XML payloads are large. If this is the case in your environment, they you will want to create some custom XML rules.

Custom XML Rules

ModSecurity can also be used to create custom rules for your WS application. Not only will this make the protection stronger and lowering the false positive rate, but you will also gain a performance boost when you specify full XPath locations in the variable list vs. the generic XML:/* variable that the Core Rules utilizes. We have created a use-case document entitled Securing Web Services with ModSecurity2 that will help to provide you with some examples of how to setup custom WS rules. Taking the previous Core Rule example, if we customize it for our WS application that is running at "/axis/getBalance.jws" and has one input parameter called "id", then the new rule would look something like this -

<Location /axis/getBalance.jws>
SecRule XML:/soap:Envelope/soap:Body/q1:getInput/id/text() "[\n\r]\s*(?:to|bcc|cc)\s*:.*?\@" \
"t:none,t:lowercase,t:urlDecode,capture,ctl:auditLogParts=+E,log,auditlog,xmlns:soap=http:// \
schemas.xmlsoap.org/soap/envelope/,xmlns:q1=http://DefaultNamespace,
msg:'Email Injection Attack. Matched signature <%{TX.0}>',id:'950019',severity:'2'"
</Location>

Notice the bolded portions of the ruleset where we have updated the XML variable to include a full XPath to our "id" input parameter and we also specified two xmlns actions to help ModSecurity to appropriately parse the payload.

Latest SpiderLabs Blogs

EDR – The Multi-Tool of Security Defenses

This is Part 8 in my ongoing project to cover 30 cybersecurity topics in 30 weekly blog posts. The full series can be found here.

Read More

The Invisible Battleground: Essentials of EASM

Know your enemy – inside and out. External Attack Surface Management tools are an effective way to understand externally facing threats and help plan cyber defenses accordingly. Let’s discuss what...

Read More

Fake Dialog Boxes to Make Malware More Convincing

Let’s explore how SpiderLabs created and incorporated user prompts, specifically Windows dialog boxes into its malware loader to make it more convincing to phishing targets during a Red Team...

Read More