Vulnerability in Open-Xchange Ox Guard
CVE-2016-4028
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.
EPSS: 0.007 (49.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Open-xchange Ox_guard
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (VDB Entry, Third Party Advisory, vdb-entry, x_refsource_SECTRACK)
- cve@mitre.org (mailing-list, x_refsource_BUGTRAQ)
Frequently asked questions
- What is CVE-2016-4028?
- CVE-2016-4028 is a high-severity vulnerability in Open-Xchange Ox Guard, classified under CWE-255. CVSS score: 7.5/10. Published 2016-12-15.
- How severe is CVE-2016-4028?
- High severity. CVSS v3 base score is 7.5 out of 10.