Arch Linux: ASA-201710-1 Critical: dnsmasq Remote Execution Matters

The package dnsmasq before version 2.78-1 is vulnerable to multiple issues including arbitrary code execution, denial of service and information disclosure.

Arch Linux Security Advisory ASA-201710-1
========================================
Severity: Critical
Date    : 2017-10-02
CVE-ID  : CVE-2017-14491 CVE-2017-14492 CVE-2017-14493 CVE-2017-14494
          CVE-2017-14495 CVE-2017-14496
Package : dnsmasq
Type    : multiple issues
Remote  : Yes
Link    : https://security.archlinux.org/AVG-421

Summary
======
The package dnsmasq before version 2.78-1 is vulnerable to multiple
issues including arbitrary code execution, denial of service and
information disclosure.

Resolution
=========
Upgrade to 2.78-1.

# pacman -Syu "dnsmasq>=2.78-1"

The problems have been fixed upstream in version 2.78.

Workaround
=========
None.

Description
==========
- CVE-2017-14491 (arbitrary code execution)

A heap buffer overflow was found in dnsmasq in the code responsible for
building DNS replies. An attacker could send crafted DNS packets to
dnsmasq which would cause it to crash or, potentially, execute
arbitrary code.

- CVE-2017-14492 (arbitrary code execution)

A heap buffer overflow was discovered in dnsmasq in the IPv6 router
advertisement (RA) handling code. An attacker on the local network
segment could send crafted RAs to dnsmasq which would cause it to crash
or, potentially, execute arbitrary code. This issue only affected
configurations using one of these options: enable-ra, ra-only, slaac,
ra-names, ra-advrouter, or ra-stateless.

- CVE-2017-14493 (arbitrary code execution)

A stack buffer overflow was found in dnsmasq in the DHCPv6 code. An
attacker on the local network could send a crafted DHCPv6 request to
dnsmasq which would cause it to a crash or, potentially, execute
arbitrary code.

- CVE-2017-14494 (information disclosure)

An information leak was found in dnsmasq in the DHCPv6 relay code. An
attacker on the local network could send crafted DHCPv6 packets to
dnsmasq causing it to forward the contents of process memory,
potentially leaking sensitive data.

- CVE-2017-14495 (denial of service)

A memory exhaustion flaw was found in dnsmasq in the EDNS0 code. An
attacker could send crafted DNS packets which would trigger memory
allocations which would never be freed, leading to unbounded memory
consumption and eventually a crash. This issue only affected
configurations using one of the options: add-mac, add-cpe-id, or add-subnet.

- CVE-2017-14496 (denial of service)

An integer underflow flaw leading to a buffer over-read was found in
dnsmasq in the EDNS0 code. An attacker could send crafted DNS packets
to dnsmasq which would cause it to crash. This issue only affected
configurations using one of the options: add-mac, add-cpe-id, or add-subnet.

Impact
=====
A remote attacker is able to execute arbitrary code, disclose sensitive
information or crash the application by sending specially crafted
packets.

References
=========
https://security.googleblog.com/2017/10/behind-masq-yet-more-dns-and-dhcp.html
https://github.com/google/security-research-pocs/tree/master/vulnerabilities/dnsmasq







https://security.archlinux.org/CVE-2017-14491
https://security.archlinux.org/CVE-2017-14492
https://security.archlinux.org/CVE-2017-14493
https://security.archlinux.org/CVE-2017-14494
https://security.archlinux.org/CVE-2017-14495
https://security.archlinux.org/CVE-2017-14496