9.8
CRITICAL CVSS 3.1
CVE-2021-47936
OpenCATS 0.9.4 Remote Code Execution via Resume Upload
Description

OpenCATS 0.9.4 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary commands by uploading malicious PHP files disguised as resume attachments. Attackers can upload PHP payloads through the careers job application endpoint and execute system commands via POST requests to the uploaded file in the upload directory.

INFO

Published Date :

May 10, 2026, 1:16 p.m.

Last Modified :

May 10, 2026, 1:16 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2021-47936 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Patch OpenCATS to prevent unauthenticated attackers from executing arbitrary commands via crafted file uploads.
  • Update OpenCATS to the latest version.
  • Restrict file upload types to safe formats.
  • Validate uploaded file contents rigorously.
  • Disable direct access to upload directories.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-47936.

URL Resource
https://github.com/opencats/OpenCATS
https://www.exploit-db.com/exploits/50585
https://www.opencats.org/
https://www.vulncheck.com/advisories/opencats-remote-code-execution-via-resume-upload
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-47936 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-47936 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2021-47936 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 10, 2026

    Action Type Old Value New Value
    Added Description OpenCATS 0.9.4 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary commands by uploading malicious PHP files disguised as resume attachments. Attackers can upload PHP payloads through the careers job application endpoint and execute system commands via POST requests to the uploaded file in the upload directory.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-306
    Added Reference https://github.com/opencats/OpenCATS
    Added Reference https://www.exploit-db.com/exploits/50585
    Added Reference https://www.opencats.org/
    Added Reference https://www.vulncheck.com/advisories/opencats-remote-code-execution-via-resume-upload
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.