cbcvebase.
CVE-2016-8864
published 2016-11-02

CVE-2016-8864: named in ISC BIND 9.x before 9.9.9-P4, 9.10.x before 9.10.4-P4, and 9.11.x before 9.11.0-P1 allows remote attackers to cause a denial of service (assertion…

PriorityP351high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
38.73%
98.4th percentile
named in ISC BIND 9.x before 9.9.9-P4, 9.10.x before 9.10.4-P4, and 9.11.x before 9.11.0-P1 allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a DNAME record in the answer section of a response to a recursive query, related to db.c and resolver.c.

Affected

42 ranges· showing 25
VendorProductVersion rangeFixed in
debianbind9< bind9 1:9.10.3.dfsg.P4-11 (bookworm)bind9 1:9.10.3.dfsg.P4-11 (bookworm)
debiandebian_linux
iscbind
iscbind
iscbind
iscbind>= 9.0.0 < 9.9.99.9.9
iscbind>= 9.10.0 < 9.10.49.10.4
iscbind9>= 0 < 1:9.10.3.dfsg.P4-111:9.10.3.dfsg.P4-11
iscbind9>= 0 < 1:9.10.3.dfsg.P4-111:9.10.3.dfsg.P4-11
iscbind9>= 0 < 1:9.10.3.dfsg.P4-111:9.10.3.dfsg.P4-11
iscbind9>= 0 < 1:9.10.3.dfsg.P4-111:9.10.3.dfsg.P4-11
redhatenterprise_linux_desktop
redhatenterprise_linux_desktop
redhatenterprise_linux_desktop
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_eus
redhatenterprise_linux_server
redhatenterprise_linux_server
redhatenterprise_linux_server
redhatenterprise_linux_server_aus

Detection & IOCsextracted from sources · hover to see the quote

  • Trigger condition: a DNAME record in the answer section of a recursive DNS response causes an assertion failure in resolver.c or db.c, crashing named. Detection should focus on DNS responses containing DNAME records in the ANSWER section directed at recursive resolvers.
  • The vulnerability is exploitable regardless of whether dnssec-validation is enabled or disabled — both code paths lead to assertion failure (valcreate() when enabled, dns_db_attach() when disabled). Detection logic should not be conditioned on DNSSEC configuration.
  • No authentication is required to exploit this vulnerability; any remote attacker able to send a crafted DNS response to a recursive resolver can trigger the crash.
  • Only recursive BIND servers are affected; authoritative-only servers are not at risk. Scope detection/monitoring to recursive resolvers.
  • Fortinet IPS signature ISC.BIND.DNAME.answer.Response.Handling.DoS can be used to detect exploitation attempts against CVE-2016-8864.
  • The assertion failure in dns_db_attach() (db.c) is triggered when the function is called a second time with a non-NULL *targetp, caused by caching a DNAME record after another record with a different name field in the ANSWER section.
  • The assertion failure in valcreate() (resolver.c) is triggered when fctx->validators is non-empty and valoptions is NULL on the second call, which occurs when a DNAME record with a different name field is cached after another record in the ANSWER section with dnssec-validation enabled.
  • ·Affected versions are ISC BIND 9.x before 9.9.9-P4, 9.10.x before 9.10.4-P4, and 9.11.x before 9.11.0-P1. Detection/patching should verify the running BIND version falls within these ranges.
  • ·FreeBSD 9.x (specifically 9.3-RELEASE) ships with a vulnerable BIND version; the fix was applied in 9.3-RELEASE-p50 (corrected 2016-11-02). Systems running FreeBSD 9.x with BIND should be patched or updated.
  • ·Red Hat Enterprise Linux 4 ships a vulnerable bind package but the status is 'Will not fix', meaning patching via RHEL channels is not available for that platform.

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
osv7.5HIGH
vendor_debian7.5HIGH
vendor_redhat7.5HIGH
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