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

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.8$0-$5k0.00

Summaryinfo

A vulnerability marked as very critical has been reported in DrayTek Vigor2960, Vigor3900 and Vigor300B. This issue affects some unknown processing of the file cgi-bin/mainfunction.cgi. The manipulation as part of Shell Metacharacter leads to injection. This vulnerability is referenced as CVE-2020-8515. Remote exploitation of the attack is possible. Furthermore, an exploit is available.

Detailsinfo

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. This issue has been fixed in Vigor3900/2960/300B v1.5.1.

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 public exploit are known. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/07/2025). The attack technique deployed by this issue is T1055 according to MITRE ATT&CK.

The exploit is available at exploit-db.com. It is declared as attacked. 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.

The vulnerability is also documented in the databases at Exploit-DB (48268) and Zero-Day.cz (567). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

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: 🔍

CNA Base Score: 9.8
CNA Vector: 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Injection
CWE: CWE-74 / CWE-707 / CWE-20
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Attacked
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

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

Price Prediction: 🔍
Current Price Estimation: 🔍

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Exploit-DB: 🔍
Zero-Day.cz: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

02/01/2020 🔍
02/01/2020 +0 days 🔍
02/03/2020 +2 days 🔍
11/07/2025 +2104 days 🔍

Sourcesinfo

Advisory: 156979
Status: Confirmed

CVE: CVE-2020-8515 (🔍)
GCVE (CVE): GCVE-0-2020-8515
GCVE (VulDB): GCVE-100-149615
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 02/03/2020 07:51
Updated: 11/07/2025 23:42
Changes: 02/03/2020 07:51 (35), 02/03/2020 07:56 (18), 03/28/2024 00:28 (18), 04/20/2024 09:45 (12), 07/02/2024 20:18 (2), 07/25/2024 20:16 (1), 08/27/2024 16:19 (3), 09/09/2024 22:29 (1), 02/05/2025 05:08 (11), 11/07/2025 23:42 (1)
Complete: 🔍
Cache ID: 216::103

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