cbcvebase.
CVE-2009-0696
published 2009-07-29

CVE-2009-0696: The dns_db_findrdataset function in db.c in named in ISC BIND 9.4 before 9.4.3-P3, 9.5 before 9.5.1-P3, and 9.6 before 9.6.1-P1, when configured as a master…

PriorityP269medium4.3CVSS 2.0
AVNACMAuNCNINAP
ITWEXPLOITVulnCheck KEV
Exploited in the wild
EPSS
12.65%
95.8th percentile
The dns_db_findrdataset function in db.c in named in ISC BIND 9.4 before 9.4.3-P3, 9.5 before 9.5.1-P3, and 9.6 before 9.6.1-P1, when configured as a master server, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via an ANY record in the prerequisite section of a crafted dynamic update message.

Affected

20 ranges
VendorProductVersion rangeFixed in
debianbind9< bind9 1:9.6.1.dfsg.P1-1 (bookworm)bind9 1:9.6.1.dfsg.P1-1 (bookworm)
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind
iscbind9>= 0 < 1:9.6.1.dfsg.P1-11:9.6.1.dfsg.P1-1
iscbind9>= 0 < 1:9.6.1.dfsg.P1-11:9.6.1.dfsg.P1-1
iscbind9>= 0 < 1:9.6.1.dfsg.P1-11:9.6.1.dfsg.P1-1
iscbind9>= 0 < 1:9.6.1.dfsg.P1-11:9.6.1.dfsg.P1-1
vmwareesxi
vmwarevmware_tools
vmwarevmware_vcenter_server
vmwarevmware_vsphere
vmwarevmware_workstation

Detection & IOCsextracted from sources · hover to see the quote

commandd1.flags = htons(0x2800)
commandd2.type2 = htons(0x00ff) [ANY record type in prerequisite section]
commandd2.class3 = htons(0x00ff) [ANY class in update section]
  • Detect crafted DNS dynamic update (opcode 0x2800) packets sent to port 53/UDP containing an ANY record type (0x00ff) in the prerequisite section; these can crash named regardless of allow-query or allow-update ACL configuration.
  • Monitor named logs for the assertion failure string 'REQUIRE(type != ((dns_rdatatype_t)dns_rdatatype_any)) failed' followed by 'exiting (due to assertion failure)' as a definitive indicator of exploitation.
  • The exploit process does not exit after sending the packet; a persistent sender repeatedly crashing named (if auto-restarted) is a behavioral indicator — look for rapid repeated named restarts correlated with a single source IP.
  • IPs explicitly denied by allow-query can still trigger the crash; do not rely on BIND ACLs as a detection bypass indicator — any source IP sending the malformed dynamic update opcode to port 53/UDP is suspect.
  • The exploit uses a fixed transaction ID of 0x1cd6 in the DNS header; this can be used as a packet-level signature for the specific PoC tool.
  • ·Configuring named to ignore dynamic updates is NOT sufficient to protect against this vulnerability; the assertion failure is triggered by the malformed packet before update permission checks occur.
  • ·Access controls (allow-query, allow-update) do not provide an effective workaround; the vulnerability affects all BIND 9 servers regardless of update configuration.
  • ·The only viable network-level mitigation is firewall-based blocking of DNS dynamic update (nsupdate) packets from reaching the nameserver on port 53/UDP.

CVSS provenance

nvdv2.04.3MEDIUMAV:N/AC:M/Au:N/C:N/I:N/A:P
osv4.3MEDIUM
vulncheck4.3MEDIUM
vendor_debian4.3HIGH
vendor_redhat4.3MEDIUM
CVEs like this are exactly what “Exploited This Week” covers.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.