SB2016053103 - Null pointer dereference in ngx_chain_to_iovec() in nginx (Alpine package)

Description

This security bulletin contains information about 1 vulnerability.

1) Null pointer dereference in ngx_chain_to_iovec() (CVE-ID: CVE-2016-4450)

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

CVSSv4: 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

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.

Remediation

Install update from vendor's website.

References

• https://git.alpinelinux.org/aports/commit/?id=1fbaa57d3e6c35e0dd9b37ced3e7b4f3dfbab621
• https://git.alpinelinux.org/aports/commit/?id=6123c2137e443bed33d0c3aa9f520199843021e3
• https://git.alpinelinux.org/aports/commit/?id=c2b7b271e326df743f057bae203706af5b8efc92