CVE-2024-12243: A flaw was found in GnuTLS, which relies on libtasn1 for ASN.1 data processing

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MEDIUM 5.3REMOTE

CVE-2024-12243 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 was found in GnuTLS, which relies on libtasn1 for ASN.1 data processing. Due to an inefficient algorithm in libtasn1, decoding certain DER-encoded certificate data can take excessive time, leading to increased resource consumption. This flaw allows a remote attacker to send a specially crafted certificate, causing GnuTLS to become unresponsive or slow, resulting in a denial-of-service condition.

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	1.3% (top 30%)
CISA exploited list	No
Weakness	CWE-407
Published	2025-02-10
Last modified	2026-10-22

Publisher (CNA): Red Hat, Inc.

Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

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 · gnutls28 · FIXED · 3.6.13-2ubuntu1.12

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.6.13-2ubuntu1.12" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · gnutls28 · FIXED · 3.7.3-4ubuntu1.6

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.7.3-4ubuntu1.6" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · gnutls28 · FIXED · 3.8.3-1.1ubuntu3.3

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.8.3-1.1ubuntu3.3" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.10 · gnutls28 · FIXED · 3.8.6-2ubuntu1.1

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.8.6-2ubuntu1.1" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 25.04 · gnutls28 · FIXED · 3.8.9-2ubuntu1

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.8.9-2ubuntu1" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · gnutls28 · FIXED · 3.7.9-2+deb12u4

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.7.9-2+deb12u4" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · gnutls28 · FIXED · 3.8.9-2

sudo apt update && sudo apt install --only-upgrade gnutls28 dpkg --compare-versions "$(dpkg-query -W -f='${Version}' gnutls28)" ge "3.8.9-2" && echo PATCHED || echo STILL-VULNERABLE

RHEL 8 · gnutls · FIXED · gnutls-3.6.16-8.el8_10.3

sudo dnf upgrade --advisory=RHSA-2025:4051 rpm -q gnutls

RHEL 9 · gnutls · FIXED · gnutls-3.8.3-6.el9

sudo dnf upgrade --advisory=RHSA-2025:7076 rpm -q gnutls

RHEL 9.2 Update Services for SAP Solutions · gnutls · FIXED · gnutls-3.7.6-21.el9_2.4

sudo dnf upgrade --advisory=RHSA-2025:17361 rpm -q gnutls

RHEL 9.4 Extended Update Support · gnutls · FIXED · gnutls-3.8.3-4.el9_4.2

sudo dnf upgrade --advisory=RHSA-2025:8020 rpm -q gnutls

RHEL 10 · gnutls · NOT AFFECTED

Alpine 3.20 · gnutls · FIXED · gnutls-3.8.12-r0

apk add --upgrade gnutls apk info -v gnutls

Alpine 3.21 · gnutls · FIXED · gnutls-3.8.12-r0

apk add --upgrade gnutls apk info -v gnutls

Alpine 3.22 · gnutls · FIXED · gnutls-3.8.12-r0

apk add --upgrade gnutls apk info -v gnutls

Alpine 3.23 · gnutls · FIXED · gnutls-3.8.11-r0

apk add --upgrade gnutls apk info -v gnutls

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2025-958 · source

sudo dnf update --advisory=ALAS2023-2025-958

Amazon Linux 2 · see advisory · FIXED · ALAS2-2025-2885 · source

sudo yum update --advisory=ALAS2-2025-2885

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.

Quick answers

How do I fix CVE-2024-12243?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2024-12243 being exploited?

CVE-2024-12243 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2024-12243 affect?

CVE-2024-12243 affects affected software. Severity is medium (CVSS 5.3). A flaw was found in GnuTLS, which relies on libtasn1 for ASN.1 data processing. Due to an inefficient algorithm in libtasn1, decoding certain DER-encoded certificate data can take excessive time, leading to increased resource consumption. T

How urgent is CVE-2024-12243?

Priority 41/100. Remotely exploitable, no login, no user action

References

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