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Fencer Vulns
high 7.5

CVE-2021-43618 json

GMP has an integer overflow with crafted inputs on 32-bit builds in `int_raw.c`, leading to buffer overflow

published 2021-11-15 4 y ago modified 2026-10-14 26 d ago also EUVD-2021-30531 , JLSEC-2026-1168

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.5%
EPSS 4.5% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

GNU Multiple Precision Arithmetic Library (GMP) through 6.2.1 has an mpz/inp_raw.c integer overflow and resultant buffer overflow via crafted input, leading to a segmentation fault on 32-bit platforms.

Patch / fix

  • julia GMP_jll 6.3.0+0
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • gmp Debian 14, Debian 13, Debian 12 2:6.2.1+dfsg-3

debian advisories DEBIAN-CVE-2021-43618

  • gmp Ubuntu 18.04 LTS 2:6.1.2+dfsg-2ubuntu0.1
  • gmp Ubuntu 20.04 LTS 2:6.2.0+dfsg-4ubuntu0.1
  • gmp Ubuntu Pro 14.04 LTS 2:5.1.3+dfsg-1ubuntu1+esm1
  • gmp Ubuntu Pro 16.04 LTS 2:6.1.0+dfsg-2ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2021-43618

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • gmp RHEL 8 1:6.1.2-11.el8
  • gmp-c++ RHEL 8 1:6.1.2-11.el8
  • gmp RHEL 9 1:6.2.0-13.el9
  • gmp-c++ RHEL 9 1:6.2.0-13.el9
  • gmp RHEL 8.8 EUS 1:6.1.2-11.el8_8.1
  • gmp-c++ RHEL 8.8 EUS 1:6.1.2-11.el8_8.1
  • gmp RHEL 8.6 EUS 1:6.1.2-11.el8_6.1
  • gmp-c++ RHEL 8.6 EUS 1:6.1.2-11.el8_6.1

red hat advisories RHSA-2024:3214RHSA-2024:1412RHSA-2024:1102RHSA-2023:6661

  • gmp SLE Module for Development Tools 15 SP3, SLE Module for Development Tools 15 SP2, SLE Module for Basesystem 15 SP3 +3 more 6.1.2-4.9.1
  • gmp SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 5.1.3-4.3.1

suse advisories SUSE-SU-2021:3946-1SUSE-SU-2021:3878-1

  • gmp openSUSE Tumbleweed 6.2.1-4.1
  • gmp openSUSE Leap 15.2 6.1.2-lp152.6.6.1
  • gmp openSUSE Leap 15.3 6.1.2-4.9.1

opensuse advisories openSUSE-SU-2024:11636-1openSUSE-SU-2021:1569-1openSUSE-SU-2021:3946-1

  • gmp AlmaLinux 8 1:6.1.2-11.el8
  • gmp-c++ AlmaLinux 8 1:6.1.2-11.el8
  • gmp AlmaLinux 9 1:6.2.0-13.el9
  • gmp-c++ AlmaLinux 9 1:6.2.0-13.el9

almalinux advisories ALSA-2024:3214ALSA-2023:6661

  • gmp Rocky Linux 9 1:6.2.0-13.el9

rocky linux advisories RLSA-2023:6661

  • gmp Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 6.2.1-r1

alpine advisories ALPINE-CVE-2021-43618

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

  • gmp CBL-Mariner 2.0 6.2.1-2

azure linux advisories AZL-6444

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-2021-43618 updated cvss 6.2

gmp: Integer overflow and resultant buffer overflow via crafted input

  • Red Hat Enterprise Linux 6 gmp Red Hat Enterprise Linux 7 gmp
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 9) gmp-c++ 6.2.0-13.el9
    fixed: vendor fix RHSA-2023:6661
  • Red Hat Enterprise Linux BaseOS (v. 8) gmp 6.1.2-11.el8, gmp-c++ 6.1.2-11.el8
    fixed: vendor fix RHSA-2024:3214
  • Red Hat Enterprise Linux BaseOS (v. 9) gmp 6.2.0-13.el9
    fixed: vendor fix RHSA-2023:6661
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) gmp 6.1.2-11.el8_6.1, gmp-c++ 6.1.2-11.el8_6.1
    fixed: vendor fix RHSA-2024:1102
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) gmp 6.1.2-11.el8_8.1, gmp-c++ 6.1.2-11.el8_8.1
    fixed: vendor fix RHSA-2024:1412
  • Red Hat RHOL 5.6 for RHEL 8 openshift-logging/kibana6-rhel8 v6.8.1-430, openshift-logging/vector-rhel8 v0.21.0-127, openshift-logging/fluentd-rhel8 v1.14.6-216, openshift-logging/eventrouter-rhel8 v0.4.0-246, openshift-logging/logging-loki-rhel8 v2.9.6-16, openshift-logging/loki-rhel8-operator v5.6.18-12, +12 more
    fixed: vendor fix RHSA-2024:2092
  • Red Hat RHOL 5.7 for RHEL 8 openshift-logging/vector-rhel8 v0.28.1-57, openshift-logging/kibana6-rhel8 v6.8.1-431, openshift-logging/fluentd-rhel8 v1.14.6-215, openshift-logging/eventrouter-rhel8 v0.4.0-248, openshift-logging/logging-loki-rhel8 v2.9.6-15, openshift-logging/loki-rhel8-operator v5.7.13-12, +12 more
    fixed: vendor fix RHSA-2024:2093

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-23-348-10 updated cvss 7.5

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation 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

Exploit prediction

4.46% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gmplib.org https://gmplib.org/list-archives/gmp-bugs/2021-September/005077.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia GCCBootstrap_jll
all versions
 no fix listed
julia GMP_jll
<6.3.0+0
6.3.0+0
julia LibStdCxx_jll
all versions
 no fix listed

Affected products

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-190 Integer Overflow or Wraparound

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.