CVE-2016-4423
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of service disruption.
- Exploit odds
- 1.9% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.9% in the next 30 days (EPSS).
- Severity: 7.5 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.9% · EPSS, next 30 days
- Weakness
- CWE-399
- Record status
- Modified
Affected
- Sensiolabs Symfony ≤ 2.3.40
- Sensiolabs Symfony 2.7.0
- Sensiolabs Symfony 2.7.1
- Sensiolabs Symfony 2.7.2
- Sensiolabs Symfony 2.7.3
- Sensiolabs Symfony 2.7.4
- Sensiolabs Symfony 2.7.5
- Sensiolabs Symfony 2.7.6
Attack profile CVSS 3.0 · 7.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2016-4423.md and follow it. Check whether this project is affected by CVE-2016-4423. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/symfony/symfony/pull/18733
- https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
- https://github.com/symfony/symfony/pull/18733
- https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
References
- http://www.debian.org/security/2016/dsa-3588
- https://github.com/symfony/symfony/pull/18733
- https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
- http://www.debian.org/security/2016/dsa-3588
- https://github.com/symfony/symfony/pull/18733
- https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session