CVE-2020-25683
Published: 19 January 2021
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. 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. The highest threat from this vulnerability is to system availability.
Priority
Status
| Package | Release | Status |
|---|---|---|
|
dnsmasq Launchpad, Ubuntu, Debian |
bionic |
Released
(2.79-1ubuntu0.2)
|
| focal |
Released
(2.80-1.1ubuntu1.2)
|
|
| groovy |
Released
(2.82-1ubuntu1.1)
|
|
| hirsute |
Released
(2.82-1ubuntu2)
|
|
| trusty |
Needs triage
|
|
| upstream |
Released
(2.83)
|
|
| xenial |
Released
(2.75-1ubuntu0.16.04.7)
|
|
| lunar |
Released
(2.82-1ubuntu2)
|
|
| impish |
Released
(2.82-1ubuntu2)
|
|
| jammy |
Released
(2.82-1ubuntu2)
|
|
| kinetic |
Released
(2.82-1ubuntu2)
|
|
| mantic |
Released
(2.82-1ubuntu2)
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.9 |
| Attack vector | Network |
| Attack complexity | High |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | None |
| Integrity impact | None |
| Availability impact | High |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |