DrayTek Vigor2960/Vigor3900/Vigor300B cgi-bin/mainfunction.cgi Shell Metacharacter injection

EntryHistoryDiffjsonxmlCTI

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.
9.8	$25k-$100k	0.00

A vulnerability was found in DrayTek Vigor2960, Vigor3900 and Vigor300B (Router Operating System) (the affected version is unknown). It has been rated as very critical. This issue affects an unknown code of the file cgi-bin/mainfunction.cgi. The manipulation as part of a Shell Metacharacter leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

DrayTek Vigor2960 1.3.1_Beta; Vigor3900 1.4.4_Beta; and Vigor300B 1.3.3_Beta, 1.4.2.1_Beta, and 1.4.4_Beta devices allow remote code execution as root (without authentication) via shell metacharacters to the cgi-bin/mainfunction.cgi URI.

The weakness was published 02/01/2020. The identification of this vulnerability is CVE-2020-8515 since 02/01/2020. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a exploit are known. The pricing for an exploit might be around USD $25k-$100k at the moment (estimation calculated on 04/20/2024). The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

It is declared as highly functional. We expect the 0-day to have been worth approximately $100k and more. The CISA Known Exploited Vulnerabilities Catalog lists this issue since 11/03/2021 with a due date of 05/03/2022:

Apply updates per vendor instructions.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Productinfo

Type

Router Operating System

Vendor

DrayTek

Name

License

commercial

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.8

VulDB Base Score: 9.8
VulDB Temp Score: 9.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 9.8
NVD Vector: 🔍

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: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Injection
CWE: CWE-74 / CWE-707
ATT&CK: T1055

Local: No
Remote: Yes

Availability: 🔍
Status: Highly functional

EPSS Score: 🔍
EPSS Percentile: 🔍

KEV Added: 🔍
KEV Due: 🔍
KEV Remediation: 🔍
KEV Ransomware: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍