Skip to content
Fencer Intel
medium 5.5

CVE-2020-27618 json

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid multi-byte input sequences in IBM136…

published 5y ago modified 26d ago also EUVD-2020-20125

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

The iconv function in the GNU C Library (aka glibc or libc6) 2.32 and earlier, when processing invalid multi-byte input sequences in IBM1364, IBM1371, IBM1388, IBM1390, and IBM1399 encodings, fails to advance the input state, which could lead to an infinite loop in applications, resulting in a denial of service, a different vulnerability from CVE-2016-10228.

Patch / fix

  • 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
  • glibc Debian 14, Debian 13, Debian 12 2.31-5

debian advisories DEBIAN-CVE-2020-27618

  • glibc Ubuntu 18.04 LTS 2.27-3ubuntu1.5
  • glibc Ubuntu 20.04 LTS 2.31-0ubuntu9.7
  • glibc Ubuntu Pro 16.04 LTS 2.23-0ubuntu11.3+esm3

ubuntu advisories UBUNTU-CVE-2020-27618

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

  • glibc RHEL 8 2.28-151.el8
  • nscd RHEL 8 2.28-151.el8
  • libnsl RHEL 8 2.28-151.el8
  • nss_db RHEL 8 2.28-151.el8
  • nss_hesiod RHEL 8 2.28-151.el8
  • glibc-utils RHEL 8 2.28-151.el8
  • glibc-common RHEL 8 2.28-151.el8
  • glibc-benchtests RHEL 8 2.28-151.el8

red hat advisories RHSA-2021:1585

  • glibc SLES 12 SP3-BCL, SLES 12 SP2-BCL 2.22-126.1
  • glibc SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +4 more 2.22-114.8.3
  • glibc SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +12 more 2.26-13.56.1
  • glibc SLES 11 SP4 LTSS EXTREME CORE 2.11.3-17.110.43.1

suse advisories SUSE-SU-2024:0759-1SUSE-SU-2022:2886-1SUSE-SU-2021:1165-1SUSE-SU-2021:0653-1

  • glibc openSUSE Tumbleweed 2.34-1.2
  • glibc openSUSE Leap 15.2 2.26-lp152.26.6.1
  • glibc-testsuite-src openSUSE Leap 15.2 2.26-lp152.26.6.1

opensuse advisories openSUSE-SU-2024:10792-1openSUSE-SU-2021:0358-1

  • nss_hesiod AlmaLinux 8 2.28-151.el8
  • glibc-benchtests AlmaLinux 8 2.28-151.el8

almalinux advisories ALSA-2021:1585

  • glibc Rocky Linux 8 2.28-151.el8

rocky linux advisories RLSA-2021:1585

  • glibc Arch Linux 2.33-1
  • lib32-glibc Arch Linux 2.33-1

arch linux advisories AVG-1320

Is CVE-2020-27618 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

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-2020-27618 updated cvss 5.5

glibc: iconv when processing invalid multi-byte input sequences fails to advance the input state, which could result in an infinite loop

  • Red Hat Enterprise Linux 5 glibc, compat-glibc Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, compat-glibc, glibc-common Red Hat Enterprise Linux 7 nscd, glibc, glibc-utils, compat-glibc, glibc-common
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 8) nscd 2.28-151.el8, glibc 2.28-151.el8, libnsl 2.28-151.el8, nss_db 2.28-151.el8, nss_hesiod 2.28-151.el8, glibc-utils 2.28-151.el8, +7 more Red Hat Enterprise Linux AppStream (v. 8) nscd 2.28-151.el8, glibc 2.28-151.el8, libnsl 2.28-151.el8, nss_db 2.28-151.el8, nss_hesiod 2.28-151.el8, glibc-utils 2.28-151.el8, +7 more Red Hat Enterprise Linux BaseOS (v. 8) nscd 2.28-151.el8, glibc 2.28-151.el8, libnsl 2.28-151.el8, nss_db 2.28-151.el8, nss_hesiod 2.28-151.el8, glibc-utils 2.28-151.el8, +7 more
    fixed: vendor fix RHSA-2021:1585

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 5.5

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

cisa ICSA-23-166-10 updated cvss 5.5

Siemens SIMATIC S7-1500 TM MFP BIOS

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
none
Automatable
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=26224 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:N/I:N/A:P

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-835 Loop with Unreachable Exit Condition

References

Sources

Fencer Intel 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.