CVE-2016-4423
Symphony Denial of Service Via Overlong Usernames
7.5
HIGH
CVSS 3.1
EPSS 1.4%
Description
The attemptAuthentication function in Component/Security/Http/Firewall/UsernamePasswordFormAuthenticationListener.php in Symfony before 2.3.41, 2.7.x before 2.7.13, 2.8.x before 2.8.6, and 3.0.x before 3.0.6 does not limit the length of a username stored in a session, which allows remote attackers to cause a denial of service (session storage consumption) via a series of authentication attempts with long, non-existent usernames.
How to fix CVE-2016-4423
To remediate CVE-2016-4423, upgrade the affected package to a fixed version below.
- —upgrade to 2.8.6+dfsg-1 or later
- —upgrade to 2.3.41 or later
- —upgrade to 2.3.41 or later
- —upgrade to 2.3.41 or later
Is CVE-2016-4423 being exploited?
Low — EPSS is 1.4%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 2.8.6+dfsg-1
- >= 2.3.0, < 2.3.41
- >= 2.3.0, < 2.3.41
- >= 2.3.0, < 2.3.41
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |