CVE-2016-4028: High severity open-xchange vulnerability
An issue was discovered in Open-Xchange OX Guard before 2.4.0-rev8. OX Guard uses an authentication token to identify and transfer guest users' credentials. The OX Guard API acts as a padding oracle by responding with different error codes depending on whether the provided token matches the encryption padding. In combination with AES-CBC, this allows attackers to guess the correct padding. Attackers may run brute-forcing attacks on the content of the guest authentication token and discover user credentials. For a practical attack vector, the guest users needs to have logged in, the content of the guest user's "OxReaderID" cookie and the value of the "auth" parameter needs to be known to the attacker.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2016-4028?
CVE-2016-4028 is classified as a high-severity vulnerability due to its potential to expose guest user credentials.
How do I fix CVE-2016-4028?
To mitigate CVE-2016-4028, update Open-Xchange OX Guard to version 2.4.0-rev8 or later.
What software is affected by CVE-2016-4028?
CVE-2016-4028 affects Open-Xchange OX Guard versions prior to 2.4.0-rev8.
What kind of attack can CVE-2016-4028 facilitate?
CVE-2016-4028 can facilitate a padding oracle attack that allows unauthorized access to guest user credentials.
Is there a workaround for CVE-2016-4028 if I cannot update immediately?
Currently, no specific workarounds are suggested for CVE-2016-4028 besides upgrading to the secured version.