Yesterday, seven Dnsmasq vulnerabilities were disclosed, collectively known as DNSPooq, that attackers can use to launch DNS Cache Poisoning, denial of service, and possibly remote code execution attacks, on affected devices.
Dnsmasq is a widely used open-source Domain Name System (DNS) forwarding application commonly installed on routers, operating systems, access points, and other networking equipment.
Vendors have started to release information on how customers can protect themselves from DNSPooq. To make it easier to find this information, BleepingComputer will be listing security advisories as they are released.
The related CVEs from JSOF’s DNSpooq advisory are listed below, along with their descriptions.
| Name | CVSS | Description |
|---|---|---|
| CVE-2020-25681 | 8.1 | Dnsmasq versions before 2.83are susceptible to a heap-based buffer overflow in sort_rrset() when DNSSEC is used. This can allow a remote attacker to write arbitrary data into target device’s memory that can lead to memory corruption and other unexpected behaviors on the target device. |
| CVE-2020-25682 | 8.1 | Dnsmasq versions before 2.83 are susceptible to buffer overflow in extract_name() function due to missing length check, when DNSSEC is enabled. This can allow a remote attacker to cause memory corruption on the target device. |
| CVE-2020-25683 | 5.9 | Dnsmasq versions before 2.83 are susceptible to a heap-based buffer overflow when DNSSEC is enabled. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in get_rdata() and cause a crash in dnsmasq, resulting in a Denial of Service. |
| CVE-2020-25687 | 5.9 | Dnsmasq versions before 2.83are vulnerable to a heap-based buffer overflow with large memcpy in sort_rrset() when DNSSEC is enabled. A remote attacker, who can create valid DNS replies, could use this flaw to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a Denial of Service. |
| CVE-2020-25684 | 4 | A lack of proper address/port check implemented in dnsmasq versions |
| CVE-2020-25685 | 4 | A lack of query resource name (RRNAME) checks implemented in dnsmasq’s versions before 2.83 reply_query function allows remote attackers to spoof DNS traffic that can lead to DNS cache poisoning. |
| CVE-2020-25686 | 4 | Multiple DNS query requests for the same resource name (RRNAME) by dnsmasq versions before 2.83 allows for remote attackers to spoof DNS traffic, using a birthday attack (RFC 5452), that can lead to DNS cache poisoning. |
BleepingComputer suggests checking this page throughout the coming days to see if new information is available for devices you may be using.
Source: List of DNSpooq vulnerability advisories, patches, and updates
