PT-2021-3539 · Dnsmasq+6 · Dnsmasq+6

Published

2021-01-19

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Updated

2024-06-15

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CVE-2020-25685

CVSS v2.0

4.3

Medium

VectorAV:N/AC:M/Au:N/C:N/I:P/A:N
Name of the Vulnerable Software and Affected Versions dnsmasq versions prior to 2.83
Description A flaw in dnsmasq allows an off-path attacker to forge a reply and get it accepted by dnsmasq due to the use of a weak hash (CRC32 or SHA-1) when checking forwarded queries in the reply query() function. This could be abused to perform a DNS Cache Poisoning attack, substantially reducing the number of attempts needed to forge a reply. The highest threat from this issue is to data integrity.
Recommendations For dnsmasq versions prior to 2.83, update to version 2.83 or later to resolve the issue. As a temporary workaround, consider restricting the use of the reply query() function in forward.c to minimize the risk of exploitation. Additionally, avoid using dnsmasq as a DNS server unless necessary, and ensure that any optional configurations allowing the use of the EOS switch as a DNS server are carefully evaluated and secured.

Fix

Inadequate Encryption Strength

Improperly Implemented Security Check for Standard

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Weakness Enumeration

Related Identifiers

ALT-PU-2021-1126
ALT-PU-2021-1167
ALT-PU-2021-1217
BDU:2021-03623
CESA-2021_0150
CESA-2021_0153
CVE-2020-25685
DSA-4844-1
MGASA-2021-0059
OESA-2021-1001
OPENSUSE-SU-2021:0124-1
OPENSUSE-SU-2021:0129-1
OPENSUSE-SU-2021_0124-1
OPENSUSE-SU-2021_0129-1
OPENSUSE-SU-2024:10721-1
RHSA-2021:0150
RHSA-2021:0151
RHSA-2021:0152
RHSA-2021:0153
RHSA-2021:0154
RHSA-2021:0155
RHSA-2021:0156
RHSA-2021:0240
RHSA-2021:0245
RHSA-2021:0395
RHSA-2021:0401
RHSA-2021_0150
RHSA-2021_0153
SUSE-SU-2021:0162-1
SUSE-SU-2021:0163-1
SUSE-SU-2021:0166-1
SUSE-SU-2021:14603-1
SUSE-SU-2021:14604-1
SUSE-SU-2021_14603-1
USN-4698-1
USN-4698-2

Affected Products

Alt Linux
Centos
Linuxmint
Red Hat
Suse
Ubuntu
Dnsmasq