Denial of service in Trustwave ModSecurity

Published: 2020-01-22 | Updated: 2023-08-21

Risk	Medium
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2019-19886 CVE-2019-25043
CWE-ID	CWE-20 CWE-755
Exploitation vector	Network
Public exploit	N/A
Vulnerable software Subscribe	ModSecurity Server applications / IDS/IPS systems, Firewalls and proxy servers
Vendor	Trustwave

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

1) Input validation error

EUVDB-ID: #VU24491

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-19886

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to insufficient validation of user-supplied input in "Transaction::addRequestHeader" in transaction.cc. A remote attacker can send specially crafted crafted requests to the server and cause a denial of service condition on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ModSecurity: 3.0.0 - 3.0.3

External links

http://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/modsecurity-denial-of-service-details-cve-2019-19886/

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.

2) Improper handling of exceptional conditions

EUVDB-ID: #VU79793