Vulnerability identifier: #VU18150

Vulnerability risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-1000656

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Flask
Web applications / CMS

Vendor: The Pallets Projects

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing JSON data in incorrect encoding. A remote attacker can supply a specially crafted JSON string and consume all available memory resources.

Successful exploitation of the vulnerability may allow an attacker to perform denial of service (DoS) attack.

Mitigation
Update to version 0.12.3.

Vulnerable software versions

Flask: 0.1 - 0.12.2

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External links
http://github.com/pallets/flask/pull/2691
http://github.com/pallets/flask/releases/tag/0.12.3
http://security.netapp.com/advisory/ntap-20190221-0001/

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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.