CVE-2021-45951
published 2022-01-01CVE-2021-45951: Dnsmasq 2.86 has a heap-based buffer overflow in check_bad_address (called from check_for_bogus_wildcard and FuzzCheckForBogusWildcard). NOTE: the vendor's…
PriorityP342critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
2.59%
83.3th percentile
Dnsmasq 2.86 has a heap-based buffer overflow in check_bad_address (called from check_for_bogus_wildcard and FuzzCheckForBogusWildcard). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| msrc | cbl2_dnsmasq_2.86-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_dnsmasq_2.89-1_on_cbl_mariner_2.0 | — | — |
| msrc | cbl2_dnsmasq_2.89-2_on_cbl_mariner_2.0 | — | — |
| msrc | cbl_mariner_2.0_arm | — | — |
| msrc | cbl_mariner_2.0_x64 | — | — |
| thekelleys | dnsmasq | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
nvdv2.07.5HIGHAV:N/AC:L/Au:N/C:P/I:P/A:P
vendor_msrc9.8CRITICAL
vendor_redhat9.8CRITICAL
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Red Hat
dnsmasq: a heap-based buffer overflow in answer_request
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45957 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in answer_request
dnsmasq: a heap-based buffer overflow in answer_request
Dnsmasq 2.86 has a heap-based buffer overflow in answer_request (called from FuzzAnswerTheRequest and fuzz_rfc1035.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: a heap-based buffer overflow in check_bad_address
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45951 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in check_bad_address
dnsmasq: a heap-based buffer overflow in check_bad_address
Dnsmasq 2.86 has a heap-based buffer overflow in check_bad_address (called from check_for_bogus_wildcard and FuzzCheckForBogusWildcard). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: a heap-based buffer overflow in extract_name
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45953 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in extract_name
dnsmasq: a heap-based buffer overflow in extract_name
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from hash_questions and fuzz_util.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: a heap-based buffer overflow in extract_name
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45954 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in extract_name
dnsmasq: a heap-based buffer overflow in extract_name
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: a heap-based buffer overflow in print_mac
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45956 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in print_mac
dnsmasq: a heap-based buffer overflow in print_mac
Dnsmasq 2.86 has a heap-based buffer overflow in print_mac (called from log_packet and dhcp_reply). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: a heap-based buffer overflow in dhcp_reply
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45952 [CRITICAL] CWE-787 dnsmasq: a heap-based buffer overflow in dhcp_reply
dnsmasq: a heap-based buffer overflow in dhcp_reply
Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 7) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 8) - Not affected
Package: dnsmasq (Red Hat Enterprise Linux 9) - Not affected
Package: dnsmasq (Red Hat OpenStack Platform 13 (Queens)) - Not affected
Red Hat
dnsmasq: heap-based buffer overflow in resize_packet
vendor_redhat·2022-01-01·CVSS 9.8
CVE-2021-45955 [CRITICAL] CWE-787 dnsmasq: heap-based buffer overflow in resize_packet
dnsmasq: heap-based buffer overflow in resize_packet
Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion. NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities, to the best of our knowledge." However, a contributor states that a security patch (mentioned in 016162.html) is needed
A heap-based out-of-bounds WRITE flaw was found in dnsmasq. A remote attacker who can trigger a packet resize can use this flaw to write up to 50 bytes to the heap via a memmove call.
Statement: Red Hat Product Security does not consider this to be a vulnerability.
Package: dnsmasq (Red Hat Enterprise Linux 6) - Not
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from hash_questions and fuzz_util.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45953 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from hash_questions and fuzz_util.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from hash_questions and fuzz_util.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to add
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in answer_request (called from FuzzAnswerTheRequest and fuzz_rfc1035.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45957 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in answer_request (called from FuzzAnswerTheRequest and fuzz_rfc1035.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not
Dnsmasq 2.86 has a heap-based buffer overflow in answer_request (called from FuzzAnswerTheRequest and fuzz_rfc1035.c). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If im
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real v
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45954 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real v
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additiona
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in print_mac (called from log_packet and dhcp_reply). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vul
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45956 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in print_mac (called from log_packet and dhcp_reply). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vul
Dnsmasq 2.86 has a heap-based buffer overflow in print_mac (called from log_packet and dhcp_reply). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vul
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45952 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vul
Dnsmasq 2.86 has a heap-based buffer overflow in dhcp_reply (called from dhcp_packet and FuzzDhcp). NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge.
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional
Microsoft
Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion. NOTE: the
vendor_msrc·2021-12-14·CVSS 9.8
CVE-2021-45955 [CRITICAL] CWE-787 Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion. NOTE: the
Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion. NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 "do not represent real vulnerabilities to the best of our knowledge." However a contributor states that a security patch (mentioned in 016162.html) is needed
FAQ: Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is compos
GHSA
GHSA-vwm2-rj6m-p924: Dnsmasq 2
ghsa_unreviewed·2022-01-02
CVE-2021-45951 [CRITICAL] CWE-787 GHSA-vwm2-rj6m-p924: Dnsmasq 2
Dnsmasq 2.86 has a heap-based buffer overflow in check_bad_address (called from check_for_bogus_wildcard and FuzzCheckForBogusWildcard).
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35868https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-924.yamlhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.htmlhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.htmlhttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35868https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-924.yamlhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.htmlhttps://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.html
2022-01-01
Published