Amazon Linux AMI update for nginx

1) Null pointer dereference in ngx_chain_to_iovec()

EUVDB-ID: #VU25

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-2016-4450

CWE-ID: CWE-829 - Inclusion of Functionality from Untrusted Control Sphere

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause denial of service conditions on the target system.

The vulnerability exists due to an access control error in the ngx_chain_to_iovec() function, when saving the client request body to a temporary file. A remote unauthenticated attacker can cause a null pointer dereference in the ngx_chain_to_iovec() function by sending specially crafted data.

Successful exploitation of this vulnerability may lead to the crash of a worker process.

Mitigation

Update the affected packages.

i686:
    nginx-debuginfo-1.8.1-3.27.amzn1.i686
    nginx-1.8.1-3.27.amzn1.i686

src:
    nginx-1.8.1-3.27.amzn1.src

x86_64:
    nginx-1.8.1-3.27.amzn1.x86_64
    nginx-debuginfo-1.8.1-3.27.amzn1.x86_64

Vulnerable software versions

Amazon Linux AMI: All versions

External links

http://alas.aws.amazon.com/ALAS-2016-715.html

Q & A

Can this vulnerability be exploited remotely?

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

Is there known malware, which exploits this vulnerability?

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