CVE-2023-1829: (Pwn2Own) Canonical Ubuntu tcindex Double-Free Local Privilege Escalation Vulnerability

Published Apr 12, 2023
·
Updated

A use-after-free vulnerability in the Linux Kernel traffic control index filter (tcindex) can be exploited to achieve local privilege escalation. The tcindexdelete function which does not properly deactivate filters in case of a perfect hashes while deleting the underlying structure which can later lead to double freeing the structure. A local attacker user can use this vulnerability to elevate its privileges to root. We recommend upgrading past commit 8c710f75256bb3cf05ac7b1672c82b92c43f3d28.

Other sources

Linux Kernel could allow a local authenticated attacker to gain elevated privileges on the system, caused by a use-after-free flaw when deleting a perfect hash filter in the tcindexdelete() function. By sending a specially crafted request, an authenticated attacker could exploit this vulnerability to gain elevated privileges.

IBM

This vulnerability allows local attackers to escalate privileges on affected installations of Canonical Ubuntu. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the tcindex module. The issue results from the lack of validating the existence of an object prior to performing further free operations on the object. An attacker can leverage this vulnerability to escalate privileges and execute code in the context of the kernel.

ZDI

Affected Software

11 affected componentsFixes available
Canonical Ubuntu
Linux Linux kernel<4.14.308
Linux Linux kernel>=4.15<4.19.276
Linux Linux kernel>=4.20<5.4.235
Linux Linux kernel>=5.5<5.10.173
Linux Linux kernel>=5.11<5.15.100
Linux Linux kernel>=5.16<6.1.18
Linux Linux kernel>=6.2<6.2.5
IBM Security Verify Governance, Identity Manager software component<=ISVG 10.0.2
IBM Security Verify Governance, Identity Manager virtual appliance component<=ISVG 10.0.2
debian/linux
5.10.223-15.10.234-16.1.129-16.1.135-16.12.27-1

Remediation

Mitigation

Block autoloading the cls_tcindex module by adding the following lines to /etc/modprobe.d/blacklist-tcindex.conf: blacklist cls_tcindex

Event History

Apr 12, 2023
CVE Published
via MITRE·11:16 AM
Data Sourced
via MITRE·11:16 AM
DescriptionSeverityWeakness
Apr 20, 2023
Data Sourced
via Red Hat·08:55 PM
DescriptionSeverityAffected Software
Feb 5, 2024
Data Sourced
via Launchpad·12:21 AM
Description
Feb 26, 2025
Advisory Published
via ZDI·07:41 PM
Apr 28, 2025
Data Sourced
via Ubuntu·02:11 PM
RemedyDescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2023-1829?

CVE-2023-1829 is considered a high-severity vulnerability that can lead to local privilege escalation in affected systems.

2

How do I fix CVE-2023-1829?

To remediate CVE-2023-1829, update your Linux kernel or IBM Security Verify Governance, Identity Manager components to the patched versions provided by the vendor.

3

Which Linux kernel versions are affected by CVE-2023-1829?

CVE-2023-1829 affects Linux kernel versions prior to 4.14.308 and versions between 4.15 and up to 6.2.5.

4

What products are affected by CVE-2023-1829?

CVE-2023-1829 impacts IBM Security Verify Governance components and multiple versions of the Linux kernel.

5

Can CVE-2023-1829 be exploited remotely?

CVE-2023-1829 is a local privilege escalation vulnerability, which means it requires local access to the affected system for exploitation.

Contact

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