GetSimpleCMS up to 3.3.15 phar File admin/upload.php unrestricted upload

HistoryDiffrelatejsonxmlCTI

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.7	$0-$5k	0.00

Summaryinfo

A vulnerability labeled as critical has been found in GetSimpleCMS up to 3.3.15. This affects an unknown function of the file admin/upload.php of the component phar File Handler. Executing a manipulation can lead to unrestricted upload. This vulnerability is registered as CVE-2021-28976. It is possible to launch the attack remotely. Furthermore, an exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in GetSimpleCMS up to 3.3.15. It has been declared as critical. This vulnerability affects an unknown part of the file admin/upload.php of the component phar File Handler. The manipulation with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability.

The weakness was published 06/23/2021. The advisory is shared for download at github.com. This vulnerability was named CVE-2021-28976. Technical details and also a public exploit are known. The MITRE ATT&CK project declares the attack technique as T1608.002.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. By approaching the search of inurl:admin/upload.php it is possible to find vulnerable targets with Google Hacking.

Upgrading to version 3.3.16 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Exploit-DB (52168). Once again VulDB remains the best source for vulnerability data.

Productinfo

Name

GetSimpleCMS

Version

Website

Product: https://github.com/GetSimpleCMS/GetSimpleCMS/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 5.7

VulDB Base Score: 6.3
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Unrestricted upload
CWE: CWE-434 / CWE-284 / CWE-266
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Download: 🔍
Google Hack: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: GetSimpleCMS 3.3.16

Timelineinfo

03/22/2021 🔍
06/23/2021 +92 days 🔍
06/23/2021 +0 days 🔍
04/13/2025 +1390 days 🔍

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2021-28976 (🔍)
GCVE (CVE): GCVE-0-2021-28976
GCVE (VulDB): GCVE-100-177460
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 06/23/2021 21:02
Updated: 04/13/2025 06:40
Changes: 06/23/2021 21:02 (38), 06/26/2021 14:07 (5), 04/13/2025 06:40 (23)
Complete: 🔍
Cache ID: 216::103