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Fencer Vulns
low 3.1

CVE-2024-6874 json

macidn punycode buffer overread

published 2024-07-24 2 y ago modified 2026-07-25 3 mo ago also EUVD-2024-47867 , JLSEC-2025-37

cvss
3.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

libcurl's URL API function [curl_url_get()](https://curl.se/libcurl/c/curl_url_get.html) offers punycode conversions, to and from IDN. Asking to convert a name that is exactly 256 bytes, libcurl ends up reading outside of a stack based buffer when built to use the *macidn* IDN backend. The conversion function then fills up the provided buffer exactly - but does not null terminate the string.

This flaw can lead to stack contents accidently getting returned as part of the converted string.

Patch / fix

  • julia LibCURL_jll 8.9.0+0
  • haxx curl 8.9.0
  • haxx libcurl 8.9.0
  • curl Debian 14, Debian 13 8.9.0-1

debian advisories DEBIAN-CVE-2024-6874

  • curl SLE Module for Basesystem 15 SP7, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 8.14.1-150600.4.28.1

suse advisories SUSE-SU-2025:03198-1

  • curl openSUSE Tumbleweed 8.9.0-1.1

opensuse advisories openSUSE-SU-2024:14225-1

  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 8.9.0-r0

alpine advisories ALPINE-CVE-2024-6874

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl CBL-Mariner 2.0, Azure Linux 3.0 8.8.0-1
  • cmake Azure Linux 3.0 3.30.3-2

azure linux advisories AZL-47020AZL-47046AZL-49664

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-6874 updated cvss 5.3

curl: macidn punycode buffer overread

  • Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl Red Hat Enterprise Linux 8 curl, libcurl, libcurl-minimal Red Hat Enterprise Linux 9 curl, libcurl, curl-minimal, libcurl-minimal Red Hat Enterprise Linux 10 curl Red Hat JBoss Core Services jbcs-httpd24-curl jbcs-httpd24-curl
    +1 more products
    Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-25-226-07 updated cvss 3.1

Siemens Third-Party Components in SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.2
    affected: fixed in V3.2 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family < 3.2
    affected: fixed in V3.2
  • Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family < 3.2
    affected: fixed in V3.2 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-26-043-06 updated cvss 3.1

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.3
    affected: fixed in V3.3 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family < 3.3
    affected: fixed in V3.3
  • Siemens SCALANCE XCH328 (6GK5328-4TS01-2EC2) < 3.3 Siemens SCALANCE XCM324 (6GK5324-8TS01-2AC2) < 3.3 Siemens SCALANCE XCM328 (6GK5328-4TS01-2AC2) < 3.3 Siemens SCALANCE XCM332 (6GK5332-0GA01-2AC2) < 3.3 Siemens SCALANCE XRH334 (24 V DC, 8xFO, CC) (6GK5334-2TS01-2ER3) < 3.3 Siemens SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) < 3.3
    +8 more products
    Siemens SCALANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) < 3.3 Siemens SCALANCE XRM334 (2x230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-4AR3) < 3.3 Siemens SCALANCE XRM334 (24 V DC, 8xFO) (6GK5334-2TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (24 V DC, 12xFO) (6GK5334-3TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (24V DC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-2AR3) < 3.3 Siemens SCALANCE XRM334 (230 V AC, 8xFO) (6GK5334-2TS01-3AR3) < 3.3 Siemens SCALANCE XRM334 (230 V AC, 12xFO) (6GK5334-3TS01-3AR3) < 3.3 Siemens SCALANCE XRM334 (230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-3AR3) < 3.3
    affected: fixed in V3.3 support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/2604391 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 3.1 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
OSV 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia LibCURL_jll
>=8.8.0+0, <8.9.0+0
8.9.0+0

Affected products

  • curl curl
  • curl libcurl

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.