VDB-172408 · CVE-2021-20305 · EUVD-2021-7730

Nettle up to 3.7.1 signature verification

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.
3.6	$0-$5k	0.00

Summaryinfo

A vulnerability described as problematic has been identified in Nettle up to 3.7.1. Impacted is an unknown function. Executing a manipulation can lead to signature verification. This vulnerability appears as CVE-2021-20305. The attack may be performed from remote. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Nettle up to 3.7.1 and classified as problematic. This vulnerability affects an unknown code block. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect confidentiality.

The weakness was presented 04/06/2021. The advisory is shared for download at bugzilla.redhat.com. This vulnerability was named CVE-2021-20305. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 236665 (Alibaba Cloud Linux 3 : 0029: gnutls and nettle (ALINUX3-SA-2021:0029)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 3.7.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (236665) and EUVD (EUVD-2021-7730). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

Nettle

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.7
VulDB Meta Temp Score: 3.6

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
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: Signature verification
CWE: CWE-347 / CWE-345
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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

Nessus ID: 236665
Nessus Name: Alibaba Cloud Linux 3 : 0029: gnutls and nettle (ALINUX3-SA-2021:0029)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Nettle 3.7.2

Timelineinfo

12/17/2020 🔍
04/06/2021 +109 days 🔍
04/06/2021 +0 days 🔍
10/14/2026 +2017 days 🔍

Sourcesinfo

Advisory: bugzilla.redhat.com
Status: Confirmed

CVE: CVE-2021-20305 (🔍)
GCVE (CVE): GCVE-0-2021-20305
GCVE (VulDB): GCVE-100-172408
EUVD: 🔍

Entryinfo

Created: 04/06/2021 08:00
Updated: 10/14/2026 13:42
Changes: 04/06/2021 08:00 (36), 04/10/2021 09:33 (5), 05/18/2025 19:12 (16), 10/14/2026 13:42 (3)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.