CVE-2024-12133: A flaw in libtasn1 causes inefficient handling of specific certificate data

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MEDIUM 5.3REMOTE

CVE-2024-12133 is a medium-severity flaw (CVSS 5.3) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw in libtasn1 causes inefficient handling of specific certificate data. When processing a large number of elements in a certificate, libtasn1 takes much longer than expected, which can slow down or even crash the system. This flaw allows an attacker to send a specially crafted certificate, causing a denial of service attack.

Why this priority

Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-407
Published	2025-02-10
Last modified	2026-10-22

Publisher (CNA): Red Hat, Inc.

Timeline

2025-02-10Published CVE record published
2026-10-22 22:17 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · retext · FIXED · 8.1.0-1.fc46 · FEDORA-2026-0602a84203 · source

sudo dnf upgrade --advisory=FEDORA-2026-0602a84203

Ubuntu 20.04 · libtasn1-6 · FIXED · 4.16.0-2ubuntu0.1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.16.0-2ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · libtasn1-6 · FIXED · 4.19.0-3ubuntu0.24.04.1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.19.0-3ubuntu0.24.04.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · libtasn1-6 · FIXED · 4.18.0-4ubuntu0.1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.18.0-4ubuntu0.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.10 · libtasn1-6 · FIXED · 4.19.0-3ubuntu0.24.10.1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.19.0-3ubuntu0.24.10.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.04 · libtasn1-6 · NOT AFFECTED

Debian 12 · libtasn1-6 · FIXED · 4.19.0-2+deb12u1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.19.0-2+deb12u1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · libtasn1-6 · FIXED · 4.20.0-1

sudo apt update && sudo apt install --only-upgrade libtasn1-6 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' libtasn1-6)" ge "4.20.0-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 8 · libtasn1 · FIXED · libtasn1-4.13-5.el8_10

sudo dnf upgrade --advisory=RHSA-2025:4049 rpm -q libtasn1

RHEL 8.4 Advanced Mission Critical Update Support · gnutls · FIXED · gnutls-3.6.14-10.el8_4.1

sudo dnf upgrade --advisory=RHSA-2026:33125 rpm -q gnutls

RHEL 8.4 Advanced Mission Critical Update Support · libtasn1 · FIXED · libtasn1-4.13-3.el8_4.1

sudo dnf upgrade --advisory=RHSA-2026:33125 rpm -q libtasn1

RHEL 8.4 Extended Update Support Long-Life Add-On · gnutls · FIXED · gnutls-3.6.14-10.el8_4.1

sudo dnf upgrade --advisory=RHSA-2026:33125 rpm -q gnutls

RHEL 8.4 Extended Update Support Long-Life Add-On · libtasn1 · FIXED · libtasn1-4.13-3.el8_4.1

sudo dnf upgrade --advisory=RHSA-2026:33125 rpm -q libtasn1

Alpine 3.20 · libtasn1 · FIXED · libtasn1-4.20.0-r0

apk add --upgrade libtasn1 apk info -v libtasn1

Alpine 3.21 · libtasn1 · FIXED · libtasn1-4.20.0-r0

apk add --upgrade libtasn1 apk info -v libtasn1

Alpine 3.22 · libtasn1 · FIXED · libtasn1-4.20.0-r0

apk add --upgrade libtasn1 apk info -v libtasn1

Alpine 3.23 · libtasn1 · FIXED · libtasn1-4.20.0-r0

apk add --upgrade libtasn1 apk info -v libtasn1

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2025-989 · source

sudo dnf update --advisory=ALAS2023-2025-989

Amazon Linux 2 · see advisory · FIXED · ALAS2-2025-2886 · source

sudo yum update --advisory=ALAS2-2025-2886

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: cert-portal.siemens.com/productcert/html/ssa-082556.html

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

References

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