NULL pointer dereference in EmbedThis GoAhead

1) NULL pointer dereference

EUVDB-ID: #VU19146

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-2018-15504

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

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

The vulnerability exists due to the server mishandles some HTTP request fields associated with time, which results in a NULL pointer dereference, as demonstrated by If-Modified-Since or If-Unmodified-Since with a month greater than 11. A remote attacker can perform a denial of service (DoS) attack.

Mitigation

Install update from vendor's website.

Vulnerable software versions

GoAhead: 2.1.5 - 4.0.0

Appweb: 4.0.0 - 7.0.1

External links

http://github.com/embedthis/appweb/commit/66067ae6d1fa08b37a270e7dc1821df52ed2daef
http://github.com/embedthis/appweb/issues/605
http://github.com/embedthis/goahead/issues/264

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.