CVE-2016-2776
published 2016-09-28CVE-2016-2776: buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows…
PriorityP181high7.5CVSS 3.0
AVNACLPRNUINSUCNINAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
89.48%
99.8th percentile
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
Affected
21 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | bind9 | < bind9 1:9.10.3.dfsg.P4-11 (bookworm) | bind9 1:9.10.3.dfsg.P4-11 (bookworm) |
| hp | hp-ux | — | — |
| isc | bind | <= 9.9.9 | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind | — | — |
| isc | bind9 | >= 0 < 1:9.10.3.dfsg.P4-11 | 1:9.10.3.dfsg.P4-11 |
| isc | bind9 | >= 0 < 1:9.10.3.dfsg.P4-11 | 1:9.10.3.dfsg.P4-11 |
| isc | bind9 | >= 0 < 1:9.10.3.dfsg.P4-11 | 1:9.10.3.dfsg.P4-11 |
| isc | bind9 | >= 0 < 1:9.10.3.dfsg.P4-11 | 1:9.10.3.dfsg.P4-11 |
| oracle | linux | — | — |
| oracle | linux | — | — |
| oracle | linux | — | — |
| oracle | solaris | — | — |
| oracle | solaris | — | — |
| oracle | vm_server | — | — |
| oracle | vm_server | — | — |
| oracle | vm_server | — | — |
Detection & IOCsextracted from sources · hover to see the quote
commandnamed assertion failure in buffer.c triggered via crafted DNS query with TSIG RR where sizeof(TSIG RR) - 16 causes buffer overflow in response construction↗
bytes↗
DNS query with TSIG RR: flags=\x00\x00, Questions=\x00\x01, Additional RRs=\x00\x01, Type TSIG=\x00\xfa, Class ANY=\x00\xff, TTL=\x00\x00\x00\x00, Data length=\x00\xfc
- →Detect crafted DNS UDP packets targeting port 53 that contain a TSIG additional record (type 0x00FA / 250) with Class ANY (0x00FF), TTL of 0, and a padded name field constructed to trigger the off-by-one in buffer.c. The TSIG RR name is padded to make sizeof(TSIG RR) - 16 equal to the sweet spot: udpsize - DNS_MESSAGE_HEADERLEN + 1. ↗
- →The exploit crafts the TSIG RR name using up to 8 label buckets with max lengths [0x3f, 0x3f, 0x3f, 0x3d, 0x3f, 0x3f, 0x3f, 0x3d] to precisely size the packet. Monitor for DNS queries with unusually large TSIG name fields composed of repeated 63-byte labels filled with alphanumeric padding. ↗
- →The assertion failure manifests as named crashing with an assertion failure in buffer.c. Monitor named process for unexpected exits or core dumps referencing buffer.c as an indicator of exploitation. ↗
- →This assertion can be triggered even if the apparent source address is not allowed to make queries (i.e. doesn't match 'allow-query'). ACL-based filtering is NOT a sufficient mitigation — any source IP can trigger the crash. ↗
- →The Metasploit module sends a single specially crafted UDP packet then checks if the server stops responding to a follow-up valid query. A named server that stops responding to DNS queries after receiving a single UDP packet to port 53 may have been exploited. ↗
- ·No workaround is available via BIND configuration. The 'allow-query' ACL does NOT prevent exploitation since the assertion can be triggered from any source address regardless of query permissions. ↗
- ·Affected versions are ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3. Patching to these versions is the only remediation. ↗
CVSS provenance
nvdv3.07.5HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvdv2.07.8HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
osv7.5HIGH
vulncheck7.5HIGH
vendor_debian7.5HIGH
vendor_redhat7.5HIGH
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BSD
FreeBSD-SA-16:28.bind: BIND remote Denial of Service vulnerability
bsd_advisories·2016-10-10·CVSS 7.5
CVE-2016-2776 [HIGH] FreeBSD-SA-16:28.bind: BIND remote Denial of Service vulnerability
FreeBSD-SA-16:28.bind Security Advisory
The FreeBSD Project
Topic: BIND remote Denial of Service vulnerability
Category: contrib
Module: bind
Announced: 2016-10-10
Credits: ISC
Affects: FreeBSD 9.x
Corrected: 2016-09-28 06:11:01 UTC (stable/9, 9.3-STABLE)
2016-10-10 07:19:16 UTC (releng/9.3, 9.3-RELEASE-p48)
CVE Name: CVE-2016-2776
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit .
I. Background
BIND 9 is an implementation of the Domain Name System (DNS) protocols.
The named(8) daemon is an Internet Domain Name Server.
II. Problem Description
Testing by ISC has uncovered a critical error condition which can occur when
a nameserver is constructing a response. A defect
Ubuntu
Bind vulnerability
vendor_ubuntu·2016-09-27
CVE-2016-2776 Bind vulnerability
Title: Bind vulnerability
Summary: Bind could be made to crash if it received specially crafted network
traffic.
It was discovered that Bind incorrectly handled building responses to
certain specially crafted requests. A remote attacker could possibly use
this issue to cause Bind to crash, resulting in a denial of service.
Instructions: In general, a standard system update will make all the necessary changes.
Red Hat
bind: assertion failure in buffer.c while building responses to a specifically constructed request
vendor_redhat·2016-09-27·CVSS 7.5
CVE-2016-2776 [HIGH] CWE-617 bind: assertion failure in buffer.c while building responses to a specifically constructed request
bind: assertion failure in buffer.c while building responses to a specifically constructed request
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
A denial of service flaw was found in the way BIND constructed a response to a query that met certain criteria. A remote attacker could use this flaw to make named exit unexpectedly with an assertion failure via a specially crafted DNS request packet.
Package: bind (Red Hat Enterprise Linux 4) - Will not fix
Debian
CVE-2016-2776: bind9 - buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9....
vendor_debian·2016·CVSS 7.5
CVE-2016-2776 [HIGH] CVE-2016-2776: bind9 - buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9....
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
Scope: local
bookworm: resolved (fixed in 1:9.10.3.dfsg.P4-11)
bullseye: resolved (fixed in 1:9.10.3.dfsg.P4-11)
forky: resolved (fixed in 1:9.10.3.dfsg.P4-11)
sid: resolved (fixed in 1:9.10.3.dfsg.P4-11)
trixie: resolved (fixed in 1:9.10.3.dfsg.P4-11)
GHSA
GHSA-jxr9-jr43-c424: buffer
ghsa_unreviewed·2022-05-13
CVE-2016-2776 [HIGH] CWE-20 GHSA-jxr9-jr43-c424: buffer
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
OSV
CVE-2016-2776: buffer
osv·2016-09-28·CVSS 7.5
CVE-2016-2776 [HIGH] CVE-2016-2776: buffer
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
VulnCheck
Oracle linux Improper Input Validation
vulncheck·2016·CVSS 7.5
CVE-2016-2776 [HIGH] Oracle linux Improper Input Validation
Oracle linux Improper Input Validation
buffer.c in named in ISC BIND 9 before 9.9.9-P3, 9.10.x before 9.10.4-P3, and 9.11.x before 9.11.0rc3 does not properly construct responses, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a crafted query.
Affected: Oracle linux
Required Action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Exploitation References: https://web.archive.org/web/20170309182143/http://www.npa.go.jp/cyberpolice/topics/?seq=19301
Exploit PoC: https://vulncheck.com/xdb/63841840badb
No detection rules found.
Exploit-DB
ISC BIND 9 - Denial of Service
exploitdb·2016-10-04
CVE-2016-2776 ISC BIND 9 - Denial of Service
ISC BIND 9 - Denial of Service
---
import socket
import struct
TARGET = ('192.168.200.10', 53)
Q_A = 1
Q_TSIG = 250
DNS_MESSAGE_HEADERLEN = 12
def build_bind_nuke(question="\x06google\x03com\x00", udpsize=512):
query_A = "\x8f\x65\x00\x00\x00\x01\x00\x00\x00\x00\x00\x01" + question + int16(Q_A) + "\x00\x01"
sweet_spot = udpsize - DNS_MESSAGE_HEADERLEN + 1
tsig_rr = build_tsig_rr(sweet_spot)
return query_A + tsig_rr
def int16(n):
return struct.pack("!H", n)
def build_tsig_rr(bind_demarshalled_size):
signature_data = ("\x00\x00\x57\xeb\x80\x14\x01\x2c\x00\x10\xd2\x2b\x32\x13\xb0\x09"
"\x46\x34\x21\x39\x58\x62\xf3\xd5\x9c\x8b\x8f\x65\x00\x00\x00\x00")
tsig_rr_extra_fields = "\x00\xff\x00\x00\x00\x00"
necessary_bytes = len(signature_data) + len(tsig_rr_extra_fields)
necessary_bytes
Metasploit
BIND TSIG Query Denial of Service
metasploit
BIND TSIG Query Denial of Service
BIND TSIG Query Denial of Service
A defect in the rendering of messages into packets can cause named to exit with an assertion failure in buffer.c while constructing a response to a query that meets certain criteria. This assertion can be triggered even if the apparent source address isn't allowed to make queries.
Bugzilla
CVE-2016-2776 bind: remote denial-of-service attack [fedora-all]
bugzilla·2016-09-27·CVSS 7.5
CVE-2016-2776 [HIGH] CVE-2016-2776 bind: remote denial-of-service attack [fedora-all]
CVE-2016-2776 bind: remote denial-of-service attack [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of Fedora.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
NOTE: this issue affects multiple supported versions of Fedora. While
Bugzilla
CVE-2016-2776 bind99: bind: remote denial-of-service attack [fedora-all]
bugzilla·2016-09-27·CVSS 7.5
CVE-2016-2776 [HIGH] CVE-2016-2776 bind99: bind: remote denial-of-service attack [fedora-all]
CVE-2016-2776 bind99: bind: remote denial-of-service attack [fedora-all]
This is an automatically created tracking bug! It was created to ensure
that one or more security vulnerabilities are fixed in affected versions
of Fedora.
For comments that are specific to the vulnerability please use bugs filed
against the "Security Response" product referenced in the "Blocks" field.
For more information see:
http://fedoraproject.org/wiki/Security/TrackingBugs
When submitting as an update, use the fedpkg template provided in the next
comment(s). This will include the bug IDs of this tracking bug as well as
the relevant top-level CVE bugs.
Please also mention the CVE IDs being fixed in the RPM changelog and the
fedpkg commit message.
NOTE: this issue affects multiple supported versions of Fedor
Bugzilla
CVE-2016-2776 bind: assertion failure in buffer.c while building responses to a specifically constructed request
bugzilla·2016-09-22·CVSS 7.5
CVE-2016-2776 [HIGH] CVE-2016-2776 bind: assertion failure in buffer.c while building responses to a specifically constructed request
CVE-2016-2776 bind: assertion failure in buffer.c while building responses to a specifically constructed request
The following flaw, reported by ISC, was found in all versions of BIND 9 (9.0.x -> 9.8.x, 9.9.0->9.9.9-P2, 9.9.3-S1->9.9.9-S3,9.10.0->9.10.4-P2):
A defect in the rendering of messages into packets can cause named to exit with an assertion failure in buffer.c while constructing a response to a query that meets certain criteria.
This assertion can be triggered even if the apparent source address isn't allowed to make queries (i.e. doesn't match 'allow-query').
This flaw is fixed in upstream versions 9.9.9-P3 and 9.10.4-P3.
Discussion:
Acknowledgments:
Name: ISC
---
Created bind tracking bugs for this issue:
Affects: fedora-all [bug 1379818]
---
Created bind99 tracking
http://rhn.redhat.com/errata/RHSA-2016-1944.htmlhttp://rhn.redhat.com/errata/RHSA-2016-1945.htmlhttp://rhn.redhat.com/errata/RHSA-2016-2099.htmlhttp://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.htmlhttp://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.htmlhttp://www.oracle.com/technetwork/topics/security/ovmbulletinoct2016-3090547.htmlhttp://www.securityfocus.com/bid/93188http://www.securitytracker.com/id/1036903https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05321107https://kb.isc.org/article/AA-01419/0https://kb.isc.org/article/AA-01435https://kb.isc.org/article/AA-01436https://kb.isc.org/article/AA-01438https://security.FreeBSD.org/advisories/FreeBSD-SA-16:28.bind.aschttps://security.gentoo.org/glsa/201610-07https://security.netapp.com/advisory/ntap-20160930-0001/https://www.exploit-db.com/exploits/40453/http://rhn.redhat.com/errata/RHSA-2016-1944.htmlhttp://rhn.redhat.com/errata/RHSA-2016-1945.htmlhttp://rhn.redhat.com/errata/RHSA-2016-2099.htmlhttp://www.oracle.com/technetwork/topics/security/bulletinoct2016-3090566.htmlhttp://www.oracle.com/technetwork/topics/security/linuxbulletinoct2016-3090545.htmlhttp://www.oracle.com/technetwork/topics/security/ovmbulletinoct2016-3090547.htmlhttp://www.securityfocus.com/bid/93188http://www.securitytracker.com/id/1036903https://h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05321107https://kb.isc.org/article/AA-01419/0https://kb.isc.org/article/AA-01435https://kb.isc.org/article/AA-01436https://kb.isc.org/article/AA-01438https://security.FreeBSD.org/advisories/FreeBSD-SA-16:28.bind.aschttps://security.gentoo.org/glsa/201610-07https://security.netapp.com/advisory/ntap-20160930-0001/https://www.exploit-db.com/exploits/40453/
2016-09-28
Published
Exploited in the wild