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AUSCERT External Security Bulletin Redistribution
ESB-2024.2311
unbound security update
16 April 2024
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AusCERT Security Bulletin Summary
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Product: unbound
Publisher: Red Hat
Operating System: Red Hat
Resolution: Patch/Upgrade
CVE Names: CVE-2023-50868 CVE-2023-50387 CVE-2024-1488
Original Bulletin:
https://access.redhat.com/errata/RHSA-2024:1804
Comment: CVSS (Max): 8.0 CVE-2024-1488 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H)
CVSS Source: Red Hat
Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H
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Red Hat Security Advisory
Synopsis: Important: unbound security update
Advisory ID: RHSA-2024:1804
Product: Red Hat Enterprise Linux AppStream EUS (v.8.6)
Advisory URL: https://access.redhat.com/errata/RHSA-2024:1804
Issue date: 2024-04-15
CVE Names: CVE-2023-50387 CVE-2023-50868 CVE-2024-1488
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1. Summary:
An update for unbound is now available for Red Hat Enterprise Linux 8.6 Extended
Update Support.
Red Hat Product Security has rated this update as having a security impact of
Important. A Common Vulnerability Scoring System (CVSS) base score, which gives
a detailed severity rating, is available for each vulnerability from the CVE
link(s) in the References section.
2. Relevant releases/architectures:
Red Hat Enterprise Linux AppStream EUS (v.8.6) - aarch64, ppc64le, x86_64, i686,
s390x
3. Description:
The unbound packages provide a validating, recursive, and caching DNS or DNSSEC
resolver.
Security Fix(es):
* bind9: KeyTrap - Extreme CPU consumption in DNSSEC validator (CVE-2023-50387)
* bind9: Preparing an NSEC3 closest encloser proof can exhaust CPU resources
(CVE-2023-50868)
Security Fix(es):
* A vulnerability was found in Unbound due to incorrect default permissions,
allowing any process outside the unbound group to modify the unbound runtime
configuration. The default combination of the "control-use-cert: no" option with
either explicit or implicit use of an IP address in the "control-interface"
option could allow improper access. If a process can connect over localhost to
port 8953, it can alter the configuration of unbound.service. This flaw allows
an unprivileged local process to manipulate a running instance, potentially
altering forwarders, allowing them to track all queries forwarded by the local
resolver, and, in some cases, disrupting resolving altogether.
To mitigate the vulnerability, a new file
"/etc/unbound/conf.d/remote-control.conf" has been added and included in the
main unbound configuration file, "unbound.conf". The file contains two
directives that should limit access to unbound.conf:
control-interface: "/run/unbound/control"
control-use-cert: "yes"
For details about these directives, run "man unbound.conf".
Updating to the version of unbound provided by this advisory should, in most
cases, address the vulnerability. To verify that your configuration is not
vulnerable, use the "unbound-control status | grep control" command. If the
output contains "control(ssl)" or "control(namedpipe)", your configuration is
not vulnerable. If the command output returns only "control", the configuration
is vulnerable because it does not enforce access only to the unbound group
members. To fix your configuration, add the line "include:
/etc/unbound/conf.d/remote-control.conf" to the end of the file
"/etc/unbound/unbound.conf". If you use a custom
"/etc/unbound/conf.d/remote-control.conf" file, add the new directives to this
file. (CVE-2024-1488)
For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE page(s)
listed in the References section.
4. Solution:
For details on how to apply this update, which includes the changes described in
this advisory, refer to:
https://access.redhat.com/articles/11258
5. Bugs fixed (https://bugzilla.redhat.com/):
2263914 - CVE-2023-50387 - bind9: KeyTrap - Extreme CPU consumption in DNSSEC
validator
2263917 - CVE-2023-50868 - bind9: Preparing an NSEC3 closest encloser proof can
exhaust CPU resources
2264183 - CVE-2024-1488 - unbound: unrestricted reconfiguration enabled to
anyone that may lead to local privilege escalation
6. Package List:
Red Hat Enterprise Linux AppStream EUS (v.8.6)
aarch64:
python3-unbound-0:1.7.3-17.el8_6.4.aarch64.rpm
python3-unbound-debuginfo-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-debuginfo-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-debugsource-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-devel-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-libs-0:1.7.3-17.el8_6.4.aarch64.rpm
unbound-libs-debuginfo-0:1.7.3-17.el8_6.4.aarch64.rpm
ppc64le:
python3-unbound-0:1.7.3-17.el8_6.4.ppc64le.rpm
python3-unbound-debuginfo-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-debuginfo-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-debugsource-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-devel-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-libs-0:1.7.3-17.el8_6.4.ppc64le.rpm
unbound-libs-debuginfo-0:1.7.3-17.el8_6.4.ppc64le.rpm
s390x:
python3-unbound-0:1.7.3-17.el8_6.4.s390x.rpm
python3-unbound-debuginfo-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-debuginfo-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-debugsource-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-devel-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-libs-0:1.7.3-17.el8_6.4.s390x.rpm
unbound-libs-debuginfo-0:1.7.3-17.el8_6.4.s390x.rpm
x86_64:
python3-unbound-0:1.7.3-17.el8_6.4.x86_64.rpm
python3-unbound-debuginfo-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-debuginfo-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-debugsource-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-devel-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-libs-0:1.7.3-17.el8_6.4.x86_64.rpm
unbound-libs-debuginfo-0:1.7.3-17.el8_6.4.x86_64.rpm
i686:
python3-unbound-debuginfo-0:1.7.3-17.el8_6.4.i686.rpm
unbound-debuginfo-0:1.7.3-17.el8_6.4.i686.rpm
unbound-debugsource-0:1.7.3-17.el8_6.4.i686.rpm
unbound-devel-0:1.7.3-17.el8_6.4.i686.rpm
unbound-libs-0:1.7.3-17.el8_6.4.i686.rpm
unbound-libs-debuginfo-0:1.7.3-17.el8_6.4.i686.rpm
Source:
unbound-0:1.7.3-17.el8_6.4.src.rpm
7. References:
https://access.redhat.com/security/cve/CVE-2023-50387
https://access.redhat.com/security/cve/CVE-2023-50868
https://access.redhat.com/security/cve/CVE-2024-1488
https://access.redhat.com/security/updates/classification/#important
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