CVE-2023-50387KeyTrap: Allocation of Resources Without Limits or Throttling in Knot Resolver

Severity
7.5HIGHNVD
EPSS
52.0%
top 2.08%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedFeb 14
Latest updateApr 24

Description

Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages14 packages

NVDnic/knot_resolver< 5.71
NVDnlnetlabs/unbound< 1.19.1
NVDpowerdns/recursor4.8.04.8.6+2
NVDthekelleys/dnsmasq< 2.90
Debianisc/bind9< 1:9.16.48-1+3

Also affects: Fedora 39, Enterprise Linux 6.0, 7.0, 8.0, 9.0

Patches

🔴Vulnerability Details

9
OSV
dnsmasq vulnerabilities2024-04-24
OSV
bind9 vulnerabilities2024-04-09
OSV
unbound vulnerabilities2024-02-28
OSV
dnsmasq vulnerabilities2024-02-26
OSV
bind9 vulnerabilities2024-02-19

🔍Detection Rules

1
Suricata
ET HUNTING - DNS Response containing multiple DNSSEC RRSIG Entries (Algorithm 14) - Possible CVE-2023-50387 Activity2024-02-20

📋Vendor Advisories

12
Ubuntu
Dnsmasq vulnerabilities2024-04-24
Ubuntu
Bind vulnerabilities2024-04-09
BSD
FreeBSD-SA-24:03.unbound: Multiple vulnerabilities in unbound2024-03-28
Ubuntu
Unbound vulnerabilities2024-02-28
Ubuntu
Dnsmasq vulnerabilities2024-02-26

🕵️Threat Intelligence

2
Bleepingcomputer
KeyTrap attack: Internet access disrupted with one DNS packet2024-02-17
Huntress
CVE-2023-50387 Vulnerability: Analysis, Detection, Removal | Huntress
CVE-2023-50387 — KeyTrap | cvebase