Allocation of resources without limits or throttling in Undertow

1) Allocation of Resources Without Limits or Throttling

EUVDB-ID: #VU112160

Risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-5379

CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability occurs when an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Undertow: - - 2.3.18

CPE2.3

• cpe:2.3:a:red_hat:undertow:*:*:*:*:*:wildfly_core:*:*
• cpe:2.3:a:red_hat:undertow:1.0.0:*:*:*:*:wildfly_core:*:*
• cpe:2.3:a:red_hat:undertow:1.0.1:*:*:*:*:wildfly_core:*:*

External links

https://access.redhat.com/errata/RHSA-2023:4509
https://access.redhat.com/errata/RHSA-2023:4509
https://access.redhat.com/errata/RHSA-2025:9582
https://access.redhat.com/errata/RHSA-2025:9583
https://access.redhat.com/security/cve/CVE-2023-5379
https://access.redhat.com/security/cve/CVE-2023-5379
https://bugzilla.redhat.com/show_bug.cgi?id=2242099
https://bugzilla.redhat.com/show_bug.cgi?id=2242099

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to send a specially crafted request to the affected application in order to exploit this vulnerability.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.