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AUSCERT External Security Bulletin Redistribution
ESB-2021.0219
USN-4698-1: Dnsmasq vulnerabilities
20 January 2021
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AusCERT Security Bulletin Summary
---------------------------------
Product: Dnsmasq
Publisher: Ubuntu
Operating System: Ubuntu
Impact/Access: Execute Arbitrary Code/Commands -- Remote/Unauthenticated
Denial of Service -- Remote/Unauthenticated
Provide Misleading Information -- Remote/Unauthenticated
Reduced Security -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2020-25687 CVE-2020-25686 CVE-2020-25685
CVE-2020-25684 CVE-2020-25683 CVE-2020-25682
CVE-2020-25681 CVE-2019-14834
Reference: ESB-2021.0217
Original Bulletin:
https://ubuntu.com/security/notices/USN-4698-1
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USN-4698-1: Dnsmasq vulnerabilities
19 January 2021
Several security issues were fixed in Dnsmasq.
Releases
o Ubuntu 20.10
o Ubuntu 20.04 LTS
o Ubuntu 18.04 LTS
o Ubuntu 16.04 LTS
Packages
o dnsmasq - Small caching DNS proxy and DHCP/TFTP server
Details
Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled
memory when sorting RRsets. A remote attacker could use this issue to cause
Dnsmasq to hang, resulting in a denial of service, or possibly execute
arbitrary code. ( CVE-2020-25681 , CVE-2020-25687 )
Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled
extracting certain names. A remote attacker could use this issue to cause
Dnsmasq to hang, resulting in a denial of service, or possibly execute
arbitrary code. ( CVE-2020-25682 , CVE-2020-25683 )
Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly
implemented address/port checks. A remote attacker could use this issue to
perform a cache poisoning attack. ( CVE-2020-25684 )
Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly
implemented query resource name checks. A remote attacker could use this
issue to perform a cache poisoning attack. ( CVE-2020-25685 )
Moshe Kol and Shlomi Oberman discovered that Dnsmasq incorrectly handled
multiple query requests for the same resource name. A remote attacker could
use this issue to perform a cache poisoning attack. ( CVE-2020-25686 )
It was discovered that Dnsmasq incorrectly handled memory during DHCP
response creation. A remote attacker could possibly use this issue to
cause Dnsmasq to consume resources, leading to a denial of service. This
issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04
LTS. ( CVE-2019-14834 )
Update instructions
The problem can be corrected by updating your system to the following package
versions:
Ubuntu 20.10
o dnsmasq - 2.82-1ubuntu1.1
o dnsmasq-base - 2.82-1ubuntu1.1
o dnsmasq-utils - 2.82-1ubuntu1.1
Ubuntu 20.04
o dnsmasq - 2.80-1.1ubuntu1.2
o dnsmasq-base - 2.80-1.1ubuntu1.2
o dnsmasq-utils - 2.80-1.1ubuntu1.2
Ubuntu 18.04
o dnsmasq - 2.79-1ubuntu0.2
o dnsmasq-base - 2.79-1ubuntu0.2
o dnsmasq-utils - 2.79-1ubuntu0.2
Ubuntu 16.04
o dnsmasq - 2.75-1ubuntu0.16.04.7
o dnsmasq-base - 2.75-1ubuntu0.16.04.7
o dnsmasq-utils - 2.75-1ubuntu0.16.04.7
After a standard system update you need to reboot your computer to make
all the necessary changes.
References
o CVE-2020-25684
o CVE-2020-25683
o CVE-2020-25686
o CVE-2020-25687
o CVE-2020-25681
o CVE-2019-14834
o CVE-2020-25682
o CVE-2020-25685
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