Undertow up to 2.0.39/2.2.10 HTTP/2 resource consumption

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.
3.4	$0-$5k	0.00

Summaryinfo

A vulnerability identified as problematic has been detected in Undertow up to 2.0.39/2.2.10. This impacts an unknown function of the component HTTP2 Handler. This manipulation causes resource consumption. This vulnerability is handled as CVE-2021-3629. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Undertow up to 2.0.39/2.2.10. It has been declared as problematic. Affected by this vulnerability is some unknown functionality of the component HTTP2 Handler. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability.

The weakness was released 05/25/2022. It is possible to read the advisory at bugzilla.redhat.com. This vulnerability is known as CVE-2021-3629 since 06/29/2021. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 240509 (RHEL 7 : Red Hat JBoss Enterprise Application Platform 7.3.14 Security update (Important) (RHSA-2025:9583)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.0.40.Final or 2.2.11.Final eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (240509). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• Undertow

Version

• 2.0.0
• 2.0.1
• 2.0.2
• 2.0.3
• 2.0.4
• 2.0.5
• 2.0.6
• 2.0.7
• 2.0.8
• 2.0.9
• 2.0.10
• 2.0.11
• 2.0.12
• 2.0.13
• 2.0.14
• 2.0.15
• 2.0.16
• 2.0.17
• 2.0.18
• 2.0.19
• 2.0.20
• 2.0.21
• 2.0.22
• 2.0.23
• 2.0.24
• 2.0.25
• 2.0.26
• 2.0.27
• 2.0.28
• 2.0.29
• 2.0.30
• 2.0.31
• 2.0.32
• 2.0.33
• 2.0.34
• 2.0.35
• 2.0.36
• 2.0.37
• 2.0.38
• 2.0.39
• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 2.2.7
• 2.2.8
• 2.2.9
• 2.2.10

License

• free

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
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: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Partially

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: 240509
Nessus Name: RHEL 7 : Red Hat JBoss Enterprise Application Platform 7.3.14 Security update (Important) (RHSA-2025:9583)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Undertow 2.0.40.Final/2.2.11.Final

Timelineinfo

06/29/2021 🔍
05/25/2022 +330 days 🔍
05/25/2022 +0 days 🔍
06/26/2025 +1128 days 🔍

Sourcesinfo

Advisory: bugzilla.redhat.com
Status: Confirmed

CVE: CVE-2021-3629 (🔍)
GCVE (CVE): GCVE-0-2021-3629
GCVE (VulDB): GCVE-100-200671

Entryinfo

Created: 05/25/2022 10:20
Updated: 06/26/2025 06:17
Changes: 05/25/2022 10:20 (38), 05/30/2022 07:08 (1), 06/26/2025 06:17 (16)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

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