CVE-2016-4028 Weak cryptography in n/a

High 7.5 Published 15 Dec 2016 Updated 6 Aug 2024

Attackers can exploit a padding oracle vulnerability in OX Guard to decrypt guest authentication tokens and steal user credentials.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2016-4028?

CVE-2016-4028 is a high-severity vulnerability in n/a, published on 15 Dec 2016. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-255

Which versions are affected by CVE-2016-4028?

It affects 1 product.

Products include Open-Xchange Ox Guard.

How do I fix CVE-2016-4028?

No fix has been published for CVE-2016-4028 yet. Limit exposure of the affected software until one is available.

Is CVE-2016-4028 being exploited?

There is no known exploitation of CVE-2016-4028 in the wild and no public exploit code.

Sources

Also known as GHSA-qxh8-75pv-8vmg.