CVE-2016-4028: open-xchange ox_guard Credentials Management Errors
Vulnerability summary
CVE-2016-4028 is a high (CVSS 7.5) Credentials Management Errors vulnerability in open-xchange ox_guard. EPSS estimates a 0.71% chance of exploitation in the next 30 days, higher than 52.6% of scored vulnerabilities.
Timeline
- 15-12-2016PublishedVulnerability first disclosed.
- 06-08-2024Last modifiedVulnerability information updated.
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.
CVSS metrics
2 scores · 1 source · 2 versionsEPSS trend
Probability
0.71%
Chance of exploitation in the next 30 days
Percentile
53%
Versus all other CVEs
30-day change
0.00 pp
From 0.71% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Open-xchange1 product
- ox_guard≤ 2.4.0
1 vendor · 1 product