Test ID:	1.3.6.1.4.1.25623.1.1.2.2021.1138
Category:	Huawei EulerOS Local Security Checks
Title:	Huawei EulerOS: Security Advisory for dnsmasq (EulerOS-SA-2021-1138)
Summary:	The remote host is missing an update for the Huawei EulerOS 'dnsmasq' package(s) announced via the EulerOS-SA-2021-1138 advisory.
Description:	Summary: The remote host is missing an update for the Huawei EulerOS 'dnsmasq' package(s) announced via the EulerOS-SA-2021-1138 advisory. Vulnerability Insight: 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 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. This flaw allows a remote attacker, who can create valid DNS replies, 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. The highest threat from this vulnerability is to system availability.(CVE-2020-25687) 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 ... [Please see the references for more information on the vulnerabilities] Affected Software/OS: 'dnsmasq' package(s) on Huawei EulerOS V2.0SP8. Solution: Please install the updated package(s). CVSS Score: 8.3 CVSS Vector: AV:N/AC:M/Au:N/C:P/I:P/A:C
Cross-Ref:	Common Vulnerability Exposure (CVE) ID: CVE-2020-25681 Debian Security Information: DSA-4844 (Google Search) https://www.debian.org/security/2021/dsa-4844 https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/QGB7HL3OWHTLEPSMLDGOMXQKG3KM2QME/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WYW3IR6APUSKOYKL5FT3ACTIHWHGQY32/ https://security.gentoo.org/glsa/202101-17 https://bugzilla.redhat.com/show_bug.cgi?id=1881875 https://www.jsof-tech.com/disclosures/dnspooq/ https://lists.debian.org/debian-lts-announce/2021/03/msg00027.html Common Vulnerability Exposure (CVE) ID: CVE-2020-25682 https://bugzilla.redhat.com/show_bug.cgi?id=1882014 Common Vulnerability Exposure (CVE) ID: CVE-2020-25683 https://bugzilla.redhat.com/show_bug.cgi?id=1882018 Common Vulnerability Exposure (CVE) ID: CVE-2020-25684 https://www.arista.com/en/support/advisories-notices/security-advisories/12135-security-advisory-61 https://bugzilla.redhat.com/show_bug.cgi?id=1889686 Common Vulnerability Exposure (CVE) ID: CVE-2020-25685 https://bugzilla.redhat.com/show_bug.cgi?id=1889688 Common Vulnerability Exposure (CVE) ID: CVE-2020-25686 https://bugzilla.redhat.com/show_bug.cgi?id=1890125 Common Vulnerability Exposure (CVE) ID: CVE-2020-25687 https://bugzilla.redhat.com/show_bug.cgi?id=1891568
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