Huawei EulerOS: Security Advisory for dnsmasq (EulerOS-SA-2021-1389)

Published: 2021-03-05 07:04:47
CVE Author: NIST National Vulnerability Database

CVSS Base Vector:
AV:N/AC:M/Au:N/C:P/I:P/A:C

Summary:
The remote host is missing an update for the Huawei EulerOS 'dnsmasq' Linux Distribution Package(s) announced via the EulerOS-SA-2021-1389 advisory.

Detection Method:
Checks if a vulnerable Linux Distribution Package version is present on the target host.

Technical Details:
A flaw was found in dnsmasq before version 2.83. When receiving a query, dnsmasq does not check for an existing pending request for the same name and forwards a new request. By default, a maximum of 150 pending queries can be sent to upstream servers, so there can be at most 150 queries for the same name. This flaw allows an off-path attacker on the network to substantially reduce the number of attempts that it would have to perform to forge a reply and have it accepted by dnsmasq. This issue is mentioned in the 'Birthday Attacks' section of RFC5452. If chained with CVE-2020-25684, the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.CVE-2020-25686 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 A flaw was found in dnsmasq before version 2.83. When getting a reply from a forwarded query, dnsmasq checks in forward.c:reply_query(), which is the forwarded query that matches the reply, by only using a weak hash of the query name. Due to the weak hash (CRC32 when dnsmasq is compiled without DNSSEC, SHA-1 when it is) this flaw allows an off-path attacker to find several different domains all having the same hash, substantially reducing the number of attempts they would have to perform to forge a reply and get it accepted by dnsmasq. This is in contrast with RFC5452, which specifies that the query name is one of the attributes of a query that must be used to match a reply. This flaw could be abused to perform a DNS Cache Poisoning attack. If chained with CVE-2020-25684 the attack complexity of a successful attack is reduced. The highest threat from this vulnerability is to data integrity.CVE-2020-25685 A flaw was found in dnsmasq. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS en ... Description truncated. Please see the references for more information.

Affected Versions:
'dnsmasq' Linux Distribution Package(s) on Huawei EulerOS Virtualization for ARM 64 3.0.2.0.

Recommendations:
Please install the updated Linux Distribution Package(s).

Solution Type:
Vendor Patch

Detection Type:
Linux Distribution Package

NIST (National Institute of Standards and Technology) NVD (National Vulnerability Database)

https://nvd.nist.gov/vuln/detail/CVE-2020-25681
https://nvd.nist.gov/vuln/detail/CVE-2020-25682
https://nvd.nist.gov/vuln/detail/CVE-2020-25683
https://nvd.nist.gov/vuln/detail/CVE-2020-25684
https://nvd.nist.gov/vuln/detail/CVE-2020-25685
https://nvd.nist.gov/vuln/detail/CVE-2020-25686
https://nvd.nist.gov/vuln/detail/CVE-2020-25687

References:


https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2021-1389

Severity
High
CVSS Score
8.3
Published
2021-03-05
Modified
2021-03-08
Category
Huawei EulerOS Local Security Checks

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