Fortinet FortiOS up to 6.4.7/7.0.2 TFTP Client line stack-based overflow

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.8$0-$5k0.00

Summaryinfo

A vulnerability has been found in Fortinet FortiOS up to 6.4.7/7.0.2 and classified as critical. This impacts an unknown function of the component TFTP Client. The manipulation of the argument line leads to stack-based overflow. This vulnerability is uniquely identified as CVE-2021-42757. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Fortinet FortiOS up to 6.4.7/7.0.2 (Firewall Software). It has been rated as critical. This issue affects an unknown part of the component TFTP Client. The manipulation of the argument line with an unknown input leads to a stack-based overflow vulnerability. Using CWE to declare the problem leads to CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). Impacted is confidentiality, integrity, and availability.

The weakness was disclosed 12/08/2021. The advisory is shared at fortiguard.com. The identification of this vulnerability is CVE-2021-42757 since 10/20/2021. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 209819 (Fortinet FortiWeb (FG-IR-21-173)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (209819) and EUVD (EUVD-2021-29715). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

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Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.9
VulDB Meta Temp Score: 6.8

VulDB Base Score: 7.2
VulDB Temp Score: 6.9
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 6.7
NVD Vector: 🔍

CNA Base Score: 6.7
CNA Vector (Fortinet, Inc.): 🔍

CVSSv2info

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

NVD Base Score: 🔍

Exploitinginfo

Class: Stack-based overflow
CWE: CWE-121 / CWE-119
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 209819
Nessus Name: Fortinet FortiWeb (FG-IR-21-173)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Timelineinfo

10/20/2021 🔍
12/08/2021 +49 days 🔍
12/08/2021 +0 days 🔍
10/16/2025 +1408 days 🔍

Sourcesinfo

Vendor: fortinet.com

Advisory: fortiguard.com
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2021-42757 (🔍)
GCVE (CVE): GCVE-0-2021-42757
GCVE (VulDB): GCVE-100-187757
EUVD: 🔍

Entryinfo

Created: 12/08/2021 14:56
Updated: 10/16/2025 12:30
Changes: 12/08/2021 14:56 (50), 12/11/2021 08:50 (2), 12/11/2021 08:54 (7), 10/28/2024 01:33 (16), 10/16/2025 12:22 (1), 10/16/2025 12:30 (11)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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