#VU75664 Information disclosure in Flask - CVE-2023-30861

Vulnerability identifier: #VU75664

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-30861

CWE-ID: CWE-200

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Flask
Web applications / CMS

Vendor: The Pallets Projects

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to missing Vary: Cookie header. A remote attacker can gain unauthorized access to sensitive information on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Flask: 2.0.0 - 2.3.1

---

External links
https://github.com/pallets/flask/releases/tag/2.3.2
https://github.com/pallets/flask/security/advisories/GHSA-m2qf-hxjv-5gpq
https://github.com/pallets/flask/releases/tag/2.2.5

---

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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