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Fencer Intel
medium 4.8

CVE-2020-29562 json

The iconv function in the GNU C Library (aka glibc or libc6) 2.30 to 2.32, when converting UCS4 text containing an irreversible character,…

published 5y ago modified 26d ago also EUVD-2020-21925

cvss
4.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 77%
public exploits
0
none known

Summary

The iconv function in the GNU C Library (aka glibc or libc6) 2.30 to 2.32, when converting UCS4 text containing an irreversible character, fails an assertion in the code path and aborts the program, potentially resulting in a denial of service.

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 2.31-7

debian advisories DEBIAN-CVE-2020-29562

  • glibc Ubuntu 18.04 LTS 2.27-3ubuntu1.5
  • glibc Ubuntu 20.04 LTS 2.31-0ubuntu9.7

ubuntu advisories UBUNTU-CVE-2020-29562

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 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

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

arch linux advisories AVG-1320

Is CVE-2020-29562 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.

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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-2020-29562 updated cvss 4.8

glibc: assertion failure in iconv when converting invalid UCS4

  • Red Hat Enterprise Linux 5 glibc Red Hat Enterprise Linux 6 nscd, glibc, glibc-utils, glibc-common Red Hat Enterprise Linux 7 nscd, glibc, glibc-utils, glibc-common Red Hat Enterprise Linux 8 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +7 more Red Hat Enterprise Linux 9 nscd, glibc, libnsl, nss_db, nss_hesiod, glibc-utils, +6 more
    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-23-348-10 updated cvss 4.8

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 4.8

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

1.68% chance of exploitation in the next 30 days, higher than 77% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=26923 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
NVD 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
CNA 3.1 4.8 CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:N/AC:H/Au:S/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

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.