#VU18298 Improper authentication in Symfony - CVE-2019-10911

Vulnerability identifier: #VU18298

Vulnerability risk: Medium

CVSSv4.0: 5.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-10911

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Symfony
Web applications / CMS

Vendor: SensioLabs

Description

The disclosed vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to the way application handles values within HTTP cookies, related to session expiration time and username. A remote attacker can modify the remember me cookie value and authenticate as a different user.

This attack is only possible if remember me functionality is enabled and the two users share a password hash or the password hashes (e.g. UserInterface::getPassword()) are null for all users (which is valid if passwords are checked by an external system, e.g. an SSO).

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Symfony: 2.7.0 - 4.2.6

---

External links
https://symfony.com/blog/cve-2019-10911-add-a-separator-in-the-remember-me-cookie-hash

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.