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Advisory details: ubuntu_osv / UBUNTU-CVE-2016-4423
Advisory ID ubuntu_osv/UBUNTU-CVE-2016-4423
Aliases CVE-2016-4423
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 6.8
Risk 3.4
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv3 7.5 https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2016/UBUNTU-CVE-2016-4423.json
ubuntu-priority medium https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2016/UBUNTU-CVE-2016-4423.json
Reference id Reference type URL
https://github.com/symfony/symfony/pull/18733
https://symfony.com/blog/cve-2016-4423-large-username-storage-in-session
https://ubuntu.com/security/CVE-2016-4423
https://www.cve.org/CVERecord?id=CVE-2016-4423
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2016/UBUNTU-CVE-2016-4423.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.