CVE-2021-24123

PowerPress <= 8.3.7 - Arbitrary File Upload

2020-10-11 00:00
Minh Tuan - SunCSR (Sun* Cyber Security Research)

Strategic Overview

Status
Patched in 8.3.8
Affected Plugin
PowerPress Podcasting plugin by Blubrry
Affected Version
<= 8.3.7
CVSS
7.2High
Weakness type
CWE-434 · Unrestricted Upload of File with Dangerous Type
CVE
CVE-2021-24123
View all PowerPress Podcasting plugin by Blubrry vulnerabilities

At a glance

CVE-2021-24123 is a high-severity Unrestricted Upload of File with Dangerous Type vulnerability in the PowerPress Podcasting plugin by Blubrry WordPress plugin, affecting versions <= 8.3.7. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). The issue is fixed in version 8.3.8; sites on affected versions should update now. Disclosed October 2020, reported by Minh Tuan - SunCSR (Sun* Cyber Security Research).

Vulnerability Overview

Arbitrary file upload in the PowerPress WordPress plugin, versions before 8.3.7, did not verify some of the uploaded feed images (such as the ones from Podcast Artwork section), allowing high privilege accounts (admin+) being able to upload arbitrary files, such as php, leading to RCE.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-434: Unrestricted Upload of File with Dangerous Type

Reaching this weakness in PowerPress Podcasting plugin by Blubrry <= 8.3.7 takes a caller who can reach the endpoint. An unrestricted file upload lets a caller store a file whose type or destination the application does not properly constrain.

If an uploaded file lands anywhere the server will execute, the flaw becomes remote code execution and the site should be treated as fully compromised. For PowerPress Podcasting plugin by Blubrry the fix is 8.3.8: builds <= 8.3.7 are affected, anything from 8.3.8 onward is not.

Remediation

Update to version 8.3.8, or a newer patched version

How does WordSec protect against this?

The attempt arrives as an ordinary request to PowerPress Podcasting plugin by Blubrry: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: PowerPress Podcasting plugin by Blubrry 8.3.8 closes this, and updating the plugin is the step that ends it.

  • Firewall
  • Scanner
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2021-24123https://www.wordfence.com/threat-intel/vulnerabilities/id/cc987edf-5a68-4baf-947c-e623c85ec659https://nvd.nist.gov/vuln/detail/CVE-2021-24123

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C