Trustwave and Cybereason Merge to Form Global MDR Powerhouse for Unparalleled Cybersecurity Value. Learn More

Trustwave and Cybereason Merge to Form Global MDR Powerhouse for Unparalleled Cybersecurity Value. Learn More

Services
Managed Detection & Response

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

Co-Managed SOC (SIEM)

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

Advisory & Diagnostics

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

Penetration Testing

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

Database Security

Prevent unauthorized access and exceed compliance requirements.

Email Security

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

Digital Forensics & Incident Response

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

Firewall & Technology Management

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

Solutions
BY TOPIC
Microsoft Security
Unlock the full power of Microsoft Security
Offensive Security
Solutions to maximize your security ROI
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

Fixing Both Missing HTTPOnly and Secure Cookie Flags

In a previous post I showed how you can use both ModSecurity and Apache together to identify/modify SessionIDs that are missing the HTTPOnly flag. I received some feedback where people were asking how to accomplish the same thing but for the "Secure" cookie flag which instructs the browser to *only* send the SessionID back over an SSL connection.

If you are only interested in addressing the missing "Secure" cookie flag, then you can simply take the example from the previous post and edit it slightly to swap out "httponly" with "secure". If, however, you want to try and address both of these issues together, then you will need to change the rule set approach a bit so that it works correctly. This is because there are now three different scenarios you have to account for -

  • Missing HTTPOnly flag
  • Missing Secure flag (if the SessionID is being sent over an SSL connection)
  • Missing both HTTPOnly and Secure flags

With this in mind, here is an updated rule set that will handle both missing HTTPOnly and Secure cooking flags.

#<_o3a_p></_o3a_p>

# First we want to capture Set-Cookie SessionID data for later inspection<_o3a_p></_o3a_p>

SecRule RESPONSE_HEADERS:/Set-Cookie2?/ "(?i:(j?sessionid|(php)?sessid|(asp|jserv|jw)?session[-_]?(id)?|cf(id|token)|sid))" "phase:3,t:none,pass,nolog,setvar:tx.sessionid=%{matched_var}"

<_o3a_p></_o3a_p>

<_o3a_p></_o3a_p>

#<_o3a_p></_o3a_p>

# We now check the saved SessionID data for the HTTPOnly flag and set an Apache<_o3a_p></_o3a_p>

# ENV variable if it is missing.<_o3a_p></_o3a_p>

SecRule TX:SESSIONID "!(?i:\;? ?httponly;?)" "phase:3,t:none,setenv:httponly_cookie=%{matched_var},pass,log,auditlog,msg:'AppDefect: Missing HttpOnly Cookie Flag.'"

<_o3a_p></_o3a_p>

<_o3a_p></_o3a_p>

#<_o3a_p></_o3a_p>

# Next we check the saved SessionID data for the Secure flag (if this is an SSL session)<_o3a_p></_o3a_p>

# and set an Apache ENV variable if it is missing.<_o3a_p></_o3a_p>

SecRule SERVER_PORT "@streq 443" "chain,phase:3,t:none,pass,log,auditlog,msg:'AppDefect: Missing Secure Cookie Flag.'"<_o3a_p></_o3a_p>

SecRule TX:SESSIONID "!(?i:\;? ?secure;?)" "t:none,setenv:secure_cookie=%{matched_var}"

<_o3a_p></_o3a_p>

<_o3a_p></_o3a_p>

#<_o3a_p></_o3a_p>

# The final check is to see if BOTH of the HTTPOnly and Secure cookie flags are missing <_o3a_p></_o3a_p>

# and set an Apache ENV variable if they are missing.<_o3a_p></_o3a_p>

SecRule TX:SESSIONID "!(?i:\;? ?httponly;?)" "chain,phase:3,t:none,pass,log,auditlog,msg:'AppDefect: Missing HttpOnly and Secure Cookie Flag.'"<_o3a_p></_o3a_p>

SecRule SERVER_PORT "@streq 443" "chain,t:none"<_o3a_p></_o3a_p>

SecRule TX:SESSIONID "!(?i:\;? ?secure;?)" "t:none,setenv:secure_httponly_cookie=%{matched_var}"

<_o3a_p></_o3a_p>

<_o3a_p></_o3a_p>

#<_o3a_p></_o3a_p>

# This last section executes the Apache Header command to

# add the appropriate Cookie flags <_o3a_p></_o3a_p>

Header set Set-Cookie "%{httponly_cookie}e; HTTPOnly" env=httponly_cookie

Header set Set-Cookie "%{secure_cookie}e; Secure" env=secure_cookie<_o3a_p></_o3a_p>

Header set Set-Cookie "%{secure_httponly_cookie}e; Secure; HTTPOnly" env=secure_httponly_cookie

These rules will both alert and fix these cookie issues. You may want to switch the actions to "nolog" so that you are not flooded with alerts.

ABOUT TRUSTWAVE

Trustwave is a globally recognized cybersecurity leader that reduces cyber risk and fortifies organizations against disruptive and damaging cyber threats. Our comprehensive offensive and defensive cybersecurity portfolio detects what others cannot, responds with greater speed and effectiveness, optimizes client investment, and improves security resilience. Learn more about us.

Latest Intelligence

Discover how our specialists can tailor a security program to fit the needs of
your organization.

Request a Demo