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Fencer Vulns
medium 6.5

CVE-2021-3826 json

Heap/stack buffer overflow in the dlang_lname function in d-demangle.c in libiberty allows attackers to potentially cause a denial of servi…

published 2022-09-01 4 y ago modified 2026-11-02 6 d ago also EUVD-2021-27075

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 74%
public exploits
0
none known

Summary

Heap/stack buffer overflow in the dlang_lname function in d-demangle.c in libiberty allows attackers to potentially cause a denial of service (segmentation fault and crash) via a crafted mangled symbol.

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
  • binutils Debian 14, Debian 13, Debian 12 2.37.50.20220121-1
  • libiberty Debian 14, Debian 13, Debian 12 20220713-1

debian advisories DEBIAN-CVE-2021-3826

  • devtoolset-12-binutils RHEL 3 SOFTWARE_COLLECTIONS 2.36.1-6.el7
  • gdb RHEL 9 10.2-11.el9
  • gdb-minimal RHEL 9 10.2-11.el9
  • gdb-headless RHEL 9 10.2-11.el9
  • gdb-gdbserver RHEL 9 10.2-11.el9

red hat advisories RHSA-2023:3269RHSA-2023:6372

  • binutils SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES 12 SP5 +6 more 2.39-9.50.1
  • cross-ppc-binutils SLE Software Development Kit 12 SP5 2.39-9.50.1
  • cross-spu-binutils SLE Software Development Kit 12 SP5 2.39-9.50.1
  • binutils SLES for SAP 15 SP2, SLES for SAP 15 SP1, SLES 15 SP2-LTSS +20 more 2.39-150100.7.40.1
  • cross-rx-binutils openSUSE Leap 15.4, openSUSE Leap 15.3 2.39-150100.7.40.1
  • cross-arm-binutils openSUSE Leap 15.4, openSUSE Leap 15.3 2.39-150100.7.40.1
  • cross-avr-binutils openSUSE Leap 15.4, openSUSE Leap 15.3 2.39-150100.7.40.1
  • cross-ppc-binutils openSUSE Leap 15.4, openSUSE Leap 15.3 2.39-150100.7.40.1

suse advisories SUSE-SU-2022:4277-1SUSE-SU-2022:4146-1

  • binutils openSUSE Tumbleweed 2.39-2.1

opensuse advisories openSUSE-SU-2024:12631-1

  • gdb AlmaLinux 9 10.2-11.el9
  • gdb-minimal AlmaLinux 9 10.2-11.el9
  • gdb-headless AlmaLinux 9 10.2-11.el9
  • gdb-gdbserver AlmaLinux 9 10.2-11.el9

almalinux advisories ALSA-2023:6372

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-2021-3826 updated cvss 6.5

libiberty: Heap/stack buffer overflow in the dlang_lname function in d-demangle.c

  • Red Hat Enterprise Linux 6 cpp, gcc, libgcc, libgcj, libitm, gcc-c++, +24 more Red Hat Enterprise Linux 7 cpp, gcc, gdb, libgo, gcc-go, libgcc, +23 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 binutils Red Hat Enterprise Linux 9 binutils, binutils-gold
    affected: no fix available “Fix deferred”
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-dashboard-rhel9
    under investigation
  • Red Hat Enterprise Linux AppStream (v. 9) gdb 10.2-11.el9, gdb-minimal 10.2-11.el9, gdb-headless 10.2-11.el9, gdb-gdbserver 10.2-11.el9
    fixed: vendor fix RHSA-2023:6372
  • Red Hat Software Collections for RHEL Workstation(v. 7) devtoolset-12-binutils 2.36.1-6.el7 Red Hat Software Collections for RHEL(v. 7) devtoolset-12-binutils 2.36.1-6.el7
    fixed: vendor fix RHSA-2023:3269
  • Red Hat Enterprise Linux 8 cpp, gcc, gdb, libgcc, libitm, gcc-c++, +35 more Red Hat Enterprise Linux 9 cpp, gcc, libgcc, libitm, gcc-c++, libasan, +16 more Red Hat Virtualization 4 cpp, gcc, libgcc, libgomp
    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 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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
31 d ago

Exploit prediction

1.50% chance of exploitation in the next 30 days, higher than 74% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected products

  • n/a gcc
  • 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-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-787 Out-of-bounds Write

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.