Input validation error in litespeed OpenLiteSpeed

1) Input validation error

EUVDB-ID: #VU36348

Risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2018-19791

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The server in LiteSpeed OpenLiteSpeed before 1.5.0 RC6 does not correctly handle requests for byte sequences, allowing an attacker to amplify the response size by requesting the entire response body repeatedly, as demonstrated by an HTTP Range header value beginning with the "bytes=0-,0-" substring.

Mitigation

Install update from vendor's website.

Vulnerable software versions

OpenLiteSpeed: 1.0.4 - 1.4.51

CPE2.3

• cpe:2.3:a:litespeedtech:litespeed:1.0.4:*:*:*:*:*:*:*
• cpe:2.3:a:litespeedtech:litespeed:1.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:litespeedtech:litespeed:1.2.2:*:*:*:*:*:*:*

External links

https://github.com/litespeedtech/openlitespeed/issues/117

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user 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.