#VU53650 Incorrect permission assignment for critical resource in Plone - CVE-2021-33509

Vulnerability identifier: #VU53650

Vulnerability risk: Medium

CVSSv4.0: 6.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-33509

CWE-ID: CWE-732

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Plone
Web applications / CMS

Vendor: Plone

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to incorrect permission assignment for critical resource. A remote authenticated attacker can perform disk I/O via crafted keyword arguments to the ReStructuredText transform in a Python script.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Plone: 5.0 rc1 - 5.2.4

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External links
https://plone.org/security/hotfix/20210518/writing-arbitrary-files-via-docutils-and-python-script
https://www.openwall.com/lists/oss-security/2021/05/22/1

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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.