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Fencer Vulns
high 7.5

CVE-2021-27219 json

An issue was discovered in GNOME GLib before 2.66.6 and 2.67.x before 2.67.3

published 2021-02-15 5 y ago modified 2026-10-14 26 d ago also EUVD-2021-13984 , JLSEC-2025-157

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.1%
EPSS 3.1% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

An issue was discovered in GNOME GLib before 2.66.6 and 2.67.x before 2.67.3. The function g_bytes_new has an integer overflow on 64-bit platforms due to an implicit cast from 64 bits to 32 bits. The overflow could potentially lead to memory corruption.

Patch / fix

  • julia Glib_jll 2.68.1+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
  • glib2.0 Debian 14, Debian 13, Debian 12 2.66.6-1

debian advisories DEBIAN-CVE-2021-27219

  • glib2.0 Ubuntu 16.04 LTS 2.48.2-0ubuntu4.7
  • glib2.0 Ubuntu 18.04 LTS 2.56.4-0ubuntu0.18.04.7
  • glib2.0 Ubuntu 20.04 LTS 2.64.6-1~ubuntu20.04.2

ubuntu advisories UBUNTU-CVE-2021-27219

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

  • redhat-virtualization-host rhev hypervisor 4.4 4.4.6-20210615.0.el8_4
  • redhat-virtualization-host-image-update rhev hypervisor 4.4 4.4.6-20210615.0.el8_4
  • mingw-glib2 RHEL 8 2.66.7-2.el8
  • mingw32-glib2 RHEL 8 2.66.7-2.el8
  • mingw64-glib2 RHEL 8 2.66.7-2.el8
  • redhat-virtualization-host RHEL 7 4.3.16-20210615.0.el7_9
  • redhat-virtualization-host-image-update RHEL 7 4.3.16-20210615.0.el7_9
  • glib2 RHEL 7 2.56.1-9.el7_9

red hat advisories RHSA-2021:2522RHSA-2021:4526RHSA-2021:2519RHSA-2021:2467RHSA-2021:2175RHSA-2021:2147

  • glib2 SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +10 more 2.54.3-4.24.1
  • glib2 SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 2.48.2-12.22.1
  • glib2 SLE Module for Basesystem 15 SP2, SLE Micro 5.0 2.62.6-3.6.1

suse advisories SUSE-SU-2021:0890-1SUSE-SU-2021:0801-1SUSE-SU-2021:0778-1

  • glib2 openSUSE Leap 15.2 2.62.6-lp152.2.6.1

opensuse advisories openSUSE-SU-2021:0406-1

  • mingw32-glib2 AlmaLinux 8 2.66.7-2.el8
  • mingw64-glib2 AlmaLinux 8 2.66.7-2.el8

almalinux advisories ALSA-2021:4526

  • glib2 Rocky Linux 8 2.56.4-10.el8_4

rocky linux advisories RLSA-2021:2170

  • glib Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 2.66.6-r0

alpine advisories ALPINE-CVE-2021-27219

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

  • glib CBL-Mariner 2.0 2.60.1-5

azure linux advisories AZL-6438

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

  • glib2 Arch Linux 2.66.6-1

arch linux advisories AVG-1574

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-2021-27219 updated cvss 9.8

glib: integer overflow in g_bytes_new function on 64-bit platforms due to an implicit cast from 64 bits to 32 bits

  • Red Hat CodeReady Linux Builder (v. 8) mingw-glib2 2.66.7-2.el8, mingw32-glib2 2.66.7-2.el8, mingw64-glib2 2.66.7-2.el8
    fixed: vendor fix RHSA-2021:2170
  • Red Hat CodeReady Linux Builder EUS (v. 8.1) glib2-doc 2.56.4-8.el8_1, glib2-static 2.56.4-8.el8_1, glib2-debuginfo 2.56.4-8.el8_1, glib2-debugsource 2.56.4-8.el8_1, glib2-fam-debuginfo 2.56.4-8.el8_1, glib2-devel-debuginfo 2.56.4-8.el8_1, +1 more
    fixed: vendor fix RHSA-2021:2172
  • Red Hat CodeReady Linux Builder EUS (v. 8.2) glib2-doc 2.56.4-8.el8_2.1, glib2-static 2.56.4-8.el8_2.1, glib2-debuginfo 2.56.4-8.el8_2.1, glib2-debugsource 2.56.4-8.el8_2.1, glib2-fam-debuginfo 2.56.4-8.el8_2.1, glib2-devel-debuginfo 2.56.4-8.el8_2.1, +1 more
    fixed: vendor fix RHSA-2021:2171
  • Red Hat Enterprise Linux BaseOS (v. 8) glib2 2.56.4-10.el8_4, glib2-fam 2.56.4-10.el8_4, glib2-tests 2.56.4-10.el8_4
    fixed: vendor fix RHSA-2021:2170
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.1) glib2 2.56.4-8.el8_1, glib2-fam 2.56.4-8.el8_1, glib2-tests 2.56.4-8.el8_1
    fixed: vendor fix RHSA-2021:2172
  • Red Hat Enterprise Linux BaseOS EUS (v. 8.2) glib2 2.56.4-8.el8_2.1, glib2-fam 2.56.4-8.el8_2.1, glib2-tests 2.56.4-8.el8_2.1
    fixed: vendor fix RHSA-2021:2171
  • Red Hat Enterprise Linux Client (v. 7) glib2 2.56.1-9.el7_9 Red Hat Enterprise Linux Client Optional (v. 7) glib2-fam 2.56.1-9.el7_9, glib2-tests 2.56.1-9.el7_9
    fixed: vendor fix RHSA-2021:2147
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) glib2 2.56.1-5.el7_6
    fixed: vendor fix RHSA-2021:2204
show 26 more
  • Red Hat Enterprise Linux ComputeNode EUS (v. 7.7) glib2 2.56.1-6.el7_7
    fixed: vendor fix RHSA-2021:2175
  • Red Hat Enterprise Linux ComputeNode Optional (v. 7) glib2-fam 2.56.1-9.el7_9, glib2-tests 2.56.1-9.el7_9
    fixed: vendor fix RHSA-2021:2147
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) glib2-fam 2.56.1-5.el7_6, glib2-tests 2.56.1-5.el7_6
    fixed: vendor fix RHSA-2021:2204
  • Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.7) glib2-fam 2.56.1-6.el7_7, glib2-tests 2.56.1-6.el7_7
    fixed: vendor fix RHSA-2021:2175
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) glib2 2.56.1-5.el7_6 Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) glib2-fam 2.56.1-5.el7_6, glib2-tests 2.56.1-5.el7_6
    fixed: vendor fix RHSA-2021:2204
  • Red Hat Enterprise Linux Server (v. 6 ELS) glib2 2.28.8-11.el6_10
    fixed: vendor fix RHSA-2021:2467
  • Red Hat Enterprise Linux Server (v. 7) glib2 2.56.1-9.el7_9
    fixed: vendor fix RHSA-2021:2147
  • Red Hat Enterprise Linux Server AUS (v. 7.2) glib2 2.42.2-6.el7_2
    fixed: vendor fix RHSA-2021:2203
  • Red Hat Enterprise Linux Server AUS (v. 7.3) glib2 2.46.2-5.el7_3
    fixed: vendor fix RHSA-2021:2173
  • Red Hat Enterprise Linux Server AUS (v. 7.4) glib2 2.50.3-4.el7_4 Red Hat Enterprise Linux Server E4S (v. 7.4) glib2 2.50.3-4.el7_4
    fixed: vendor fix RHSA-2021:2174
  • Red Hat Enterprise Linux Server EUS (v. 7.6) glib2 2.56.1-5.el7_6
    fixed: vendor fix RHSA-2021:2204
  • Red Hat Enterprise Linux Server EUS (v. 7.7) glib2 2.56.1-6.el7_7
    fixed: vendor fix RHSA-2021:2175
  • Red Hat Enterprise Linux Server Optional (v. 6 ELS) glib2-doc 2.28.8-11.el6_10, glib2-static 2.28.8-11.el6_10, glib2-debuginfo 2.28.8-11.el6_10
    fixed: vendor fix RHSA-2021:2467
  • Red Hat Enterprise Linux Server Optional (v. 7) glib2-fam 2.56.1-9.el7_9, glib2-tests 2.56.1-9.el7_9
    fixed: vendor fix RHSA-2021:2147
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.2) glib2-fam 2.42.2-6.el7_2
    fixed: vendor fix RHSA-2021:2203
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.3) glib2-fam 2.46.2-5.el7_3
    fixed: vendor fix RHSA-2021:2173
  • Red Hat Enterprise Linux Server Optional AUS (v. 7.4) glib2-fam 2.50.3-4.el7_4, glib2-tests 2.50.3-4.el7_4 Red Hat Enterprise Linux Server Optional E4S (v. 7.4) glib2-fam 2.50.3-4.el7_4, glib2-tests 2.50.3-4.el7_4
    fixed: vendor fix RHSA-2021:2174
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.6) glib2-fam 2.56.1-5.el7_6, glib2-tests 2.56.1-5.el7_6
    fixed: vendor fix RHSA-2021:2204
  • Red Hat Enterprise Linux Server Optional EUS (v. 7.7) glib2-fam 2.56.1-6.el7_7, glib2-tests 2.56.1-6.el7_7
    fixed: vendor fix RHSA-2021:2175
  • Red Hat Enterprise Linux Server Optional TUS (v. 7.4) glib2-fam 2.50.3-4.el7_4, glib2-tests 2.50.3-4.el7_4 Red Hat Enterprise Linux Server TUS (v. 7.4) glib2 2.50.3-4.el7_4
    fixed: vendor fix RHSA-2021:2174
  • Red Hat Enterprise Linux Workstation (v. 7) glib2 2.56.1-9.el7_9 Red Hat Enterprise Linux Workstation Optional (v. 7) glib2-fam 2.56.1-9.el7_9, glib2-tests 2.56.1-9.el7_9
    fixed: vendor fix RHSA-2021:2147
  • Red Hat Migration Toolkit 1.4 rhmtc/openshift-migration-ui-rhel8 v1.4.6-4, rhmtc/openshift-velero-plugin-rhel8 v1.4.6-4, rhmtc/openshift-migration-velero-rhel8 v1.4.6-5, rhmtc/openshift-migration-registry-rhel8 v1.4.6-4, rhmtc/openshift-migration-operator-bundle v1.4.6-5, rhmtc/openshift-migration-controller-rhel8 v1.4.6-4, +7 more
    fixed: vendor fix RHBA-2021:2854
  • Red Hat Virtualization 4 Hypervisor for RHEL 7 redhat-virtualization-host 4.3.16-20210615.0.el7_9, redhat-virtualization-host-image-update 4.3.16-20210615.0.el7_9
    fixed: vendor fix RHSA-2021:2519
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 redhat-virtualization-host 4.4.6-20210615.0.el8_4, redhat-virtualization-host-image-update 4.4.6-20210615.0.el8_4
    fixed: vendor fix RHSA-2021:2522
  • Red Hat RHEL 7-based RHEV-H for RHEV 4 (build requirements) redhat-virtualization-host 4.3.16-20210615.0.el7_9, redhat-virtualization-host-image-update 4.3.16-20210615.0.el7_9
    fixed: vendor fix RHSA-2021:2519
  • Red Hat Enterprise Linux 6 firefox, thunderbird
    not affected: vulnerable code not present

3 more not affected in the full advisory

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

3.06% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • gitlab.gnome.org https://gitlab.gnome.org/GNOME/glib/-/issues/2319 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 Glib_jll
<2.68.1+0
2.68.1+0

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-681 Incorrect Conversion between Numeric Types

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.