Alpine: multiple dnsmasq packages: security update to 2.82-r0 (deprecated)

high Tenable Self-Hosted Container Security Plugin ID 400304

Description

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

- A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq
extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who
can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-
allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name()
function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the
buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from
the base buffer, thus reducing, in practice, the number of available bytes that can be written in the
buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as
system availability. (CVE-2020-25682)

- A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in the way
RRSets are sorted before validating with DNSSEC data. An attacker on the network, who can forge DNS
replies such as that they are accepted as valid, could use this flaw to cause a buffer overflow with
arbitrary data in a heap memory segment, possibly executing code on the machine. The highest threat from
this vulnerability is to data confidentiality and integrity as well as system availability.
(CVE-2020-25681)

- 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. (CVE-2020-25683)

- A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq
checks in the forward.c:reply_query() if the reply destination address/port is used by the pending
forwarded queries. However, it does not use the address/port to retrieve the exact forwarded query,
substantially reducing the number of attempts an attacker on the network would have to perform to forge a
reply and get it accepted by dnsmasq. This issue contrasts with RFC5452, which specifies a query's
attributes that all must be used to match a reply. This flaw allows an attacker to perform a DNS Cache
Poisoning attack. If chained with CVE-2020-25685 or CVE-2020-25686, the attack complexity of a successful
attack is reduced. The highest threat from this vulnerability is to data integrity. (CVE-2020-25684)

Plugin Details

Severity: High

ID: 400304

Version: Revision 1.35

Type: Local

Family: Alpine Linux Local Security Checks

Published: 8/16/2023

Updated: 12/22/2025

Supported Sensors: Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 97.36

CVSS v2

Risk Factor: High

Base Score: 8.3

Temporal Score: 6.1

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:C

CVSS Score Source: CVE-2020-25682

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 1/19/2021

Vulnerability Publication Date: 1/19/2021

Reference Information

CVE: CVE-2020-25681, CVE-2020-25682, CVE-2020-25683, CVE-2020-25684, CVE-2020-25685, CVE-2020-25686, CVE-2020-25687

IAVA: 2021-A-0041

Detections

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