cbcvebase.
CVE-2015-5477
published 2015-07-29

CVE-2015-5477: named in ISC BIND 9.x before 9.9.7-P2 and 9.10.x before 9.10.2-P3 allows remote attackers to cause a denial of service (REQUIRE assertion failure and daemon…

PriorityP277high7.8CVSS 2.0
AVNACLAuNCNINAC
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
91.28%
99.8th percentile
named in ISC BIND 9.x before 9.9.7-P2 and 9.10.x before 9.10.2-P3 allows remote attackers to cause a denial of service (REQUIRE assertion failure and daemon exit) via TKEY queries.

Affected

9 ranges
VendorProductVersion rangeFixed in
appleos_x_server_v4.1.5
debianbind9< bind9 1:9.9.5.dfsg-11 (bookworm)bind9 1:9.9.5.dfsg-11 (bookworm)
iscbind<= 9.9.7
iscbind<= 9.10.2
iscbind9>= 0 < 1:9.9.5.dfsg-111:9.9.5.dfsg-11
iscbind9>= 0 < 1:9.9.5.dfsg-111:9.9.5.dfsg-11
iscbind9>= 0 < 1:9.9.5.dfsg-111:9.9.5.dfsg-11
iscbind9>= 0 < 1:9.9.5.dfsg-111:9.9.5.dfsg-11
iscbind9>= 0 < 1:9.9.5.dfsg-3ubuntu0.41:9.9.5.dfsg-3ubuntu0.4

Detection & IOCsextracted from sources · hover to see the quote

port53/UDP
bytes
4d5501000001000000000001034141410341414100 00f900ff034141410341414100000a00ff000000000009084141414141414141
bytes
01020100000100000000000103666f6f03626172000000f900ff03666f6f03626172000000100000ff000000000033
  • Detect malformed TKEY (type 249 / 0x00f9) DNS queries over UDP port 53 where the question section contains a TKEY record type (249) but the additional records section contains a non-TKEY record type (e.g., type 16) with the same query name — this is the specific packet structure that triggers the REQUIRE assertion failure in named.
  • The exploit is effective against both recursive and authoritative BIND named servers; ACLs and configuration-based access restrictions do NOT mitigate the attack because the vulnerable code path is reached before those checks are enforced.
  • Monitor named process for unexpected exits with 'REQUIRE assertion failure' in logs — this is the crash signature produced by a successful exploit of CVE-2015-5477.
  • The PoC sends a UDP DNS packet with transaction ID 0x4d55 (Python PoC) or 0x0102 (C PoC) — these static XIDs can serve as a signature for the specific PoC tools in network traffic.
  • The Metasploit auxiliary module for this CVE targets BIND versions 9.1.0 through 9.8.x, 9.9.0 through 9.9.7-P1, and 9.10.0 through 9.10.2-P2; use version fingerprinting to prioritize patching of in-range instances.
  • ·ACLs and configuration options that restrict or deny DNS service do NOT prevent exploitation because the vulnerable TKEY handling code is reached before those access controls are evaluated.

CVSS provenance

nvdv2.07.8HIGHAV:N/AC:L/Au:N/C:N/I:N/A:C
osv7.8HIGH
vulncheck7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
vendor_ubuntu7.1HIGH
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