Summary 

A flaw was found in how GLib’s GString manages memory when adding data to strings. If a string is already very large, combining it with more input can cause a hidden overflow in the size calculation. This makes the system think it has enough memory when it doesn’t. As a result, data may be written past the end of the allocated memory, leading to crashes or memory corruption.

Products Affected

• Brocade Fabric OS versions 10.0.0 through 10.0.0a1
  Note that the practical exploitability in FOS is extremely low

Products Not Affected

• Brocade Fabric OS versions before 10.0.0
  [VEX Justification: Code_not_present]
• Brocade SANnav is not affected by this vulnerability
  [VEX Justification: Vulnerable_code_cannot_be_contolled_by_adversary ]
• Brocade ASCG is not affected by this vulnerability
  [VEX Justification: Component_not_present]

Solution

• Security update provided in Brocade Fabric OS version 10.0.1
• While Brocade SANnav is not exploitable, a security update is provided in Brocade SANnav versions 3.0.0a and 3.0.1 

Revision History

Disclaimer

THIS DOCUMENT IS PROVIDED ON AN AS-IS BASIS SOLELY FOR INFORMATIONAL PURPOSES AND DOES NOT IMPLY ANY KIND OF GUARANTY OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. YOUR USE OF THE INFORMATION CONTAINED HEREIN IS AT YOUR OWN RISK. ALL INFORMATION PROVIDED HEREIN IS BASED ON BROCADE'S CURRENT KNOWLEDGE AND UNDERSTANDING OF THE VULNERABILITY AND IMPACT TO BROCADE HARDWARE AND SOFTWARE PRODUCTS. BROCADE RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.