SB2019091740 - NULL pointer dereference in asterisk (Alpine package)

Description

This security bulletin contains information about 1 security vulnerability.

1) NULL pointer dereference (CVE-ID: CVE-2019-13161)

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

An issue was discovered in Asterisk Open Source through 13.27.0, 14.x and 15.x through 15.7.2, and 16.x through 16.4.0, and Certified Asterisk through 13.21-cert3. A pointer dereference in chan_sip while handling SDP negotiation allows an attacker to crash Asterisk when handling an SDP answer to an outgoing T.38 re-invite. To exploit this vulnerability an attacker must cause the chan_sip module to send a T.38 re-invite request to them. Upon receipt, the attacker must send an SDP answer containing both a T.38 UDPTL stream and another media stream containing only a codec (which is not permitted according to the chan_sip configuration).

Remediation

Install update from vendor's website.

References

• https://git.alpinelinux.org/aports/commit/?id=fd0aefe7beb083e683ebb7f904469d01e2b71f16
• https://git.alpinelinux.org/aports/commit/?id=b8ed9736efcaee1cfb71d1c71773d8e62ee169d8
• https://git.alpinelinux.org/aports/commit/?id=de555bb30f216410e565ff8c6e8983703d16d648
• https://git.alpinelinux.org/aports/commit/?id=3037ceeb75de0f253b86db6e56d7e28eeb95cbf6