ASA-2018-00046 – Asterisk: Remote buffer overflow in DNS SRV and NAPTR lookups


Allele Security Alert

ASA-2018-00046

Identifier(s)

ASA-2018-00046, AST-2018-010, CVE-2018-19278

Title

Remote buffer overflow in DNS SRV and NAPTR lookups

Vendor(s)

Digium, Inc

Product(s)

Asterisk Open Source

Affected version(s)

Asterisk Open Source 15.x all releases
Asterisk Open Source 16.x all releases

Fixed version(s)

Asterisk Open Source 15.6.2
Asterisk Open Source 16.0.1

Proof of concept

Unknown

Description

There is a buffer overflow vulnerability in dns_srv_alloc() and dns_naptr_alloc() functions of Asterisk that allows an attacker to crash Asterisk via a specially crafted DNS SRV or NAPTR response. The attacker€™s request causes Asterisk to segfault and crash.

In both functions, dn_expand is used to expand a compressed domain name. The return value is used to calculate the size of the buffer for the ast_dns_srv_record/ast_dns_naptr_record struct, where the expanded domain name will be stored. However, the return value of dn_expand is actually the length of the compressed domain name, so this can lead to a buffer overflow.

Technical details

Unknown

Credits

Jan Hoffmann

Reference(s)

AST-2018-010: Remote crash vulnerability DNS SRV and NAPTR lookups
https://seclists.org/fulldisclosure/2018/Nov/42

AST-2018-010-15.diff
http://downloads.asterisk.org/pub/security/AST-2018-010-15.diff

AST-2018-010-16.diff
http://downloads.asterisk.org/pub/security/AST-2018-010-16.diff

Buffer overflow for DNS SRV/NAPTR records
https://issues.asterisk.org/jira/browse/ASTERISK-28127

Asterisk Project Security Advisory – AST-2018-010
https://downloads.asterisk.org/pub/security/AST-2018-010.pdf

Asterisk Project Security Advisory – AST-2018-010
https://downloads.asterisk.org/pub/security/AST-2018-010.html

CVE-2018-19278
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-19278

CVE-2018-19278
https://nvd.nist.gov/vuln/detail/CVE-2018-19278

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Last modified: March 1, 2019

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