Critical: dnsmasq

Issue Overview:

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-2017-14495)

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. (CVE-2017-14496)

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-2017-14493)

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-2017-14494)

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-2017-14492)

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-2017-14491)

Affected Packages:

dnsmasq

Note:

This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.

Issue Correction:
Run yum update dnsmasq to update your system.

New Packages:

aarch64:  
    dnsmasq-2.76-5.amzn2.aarch64  
    dnsmasq-utils-2.76-5.amzn2.aarch64  
    dnsmasq-debuginfo-2.76-5.amzn2.aarch64  
  
i686:  
    dnsmasq-2.76-5.amzn2.i686  
    dnsmasq-utils-2.76-5.amzn2.i686  
    dnsmasq-debuginfo-2.76-5.amzn2.i686  
  
src:  
    dnsmasq-2.76-5.amzn2.src  
  
x86_64:  
    dnsmasq-2.76-5.amzn2.x86_64  
    dnsmasq-utils-2.76-5.amzn2.x86_64  
    dnsmasq-debuginfo-2.76-5.amzn2.x86_64  

Additional References

Red Hat: CVE-2017-14491, CVE-2017-14492, CVE-2017-14493, CVE-2017-14494, CVE-2017-14495, CVE-2017-14496

Mitre: CVE-2017-14491, CVE-2017-14492, CVE-2017-14493, CVE-2017-14494, CVE-2017-14495, CVE-2017-14496