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Fencer Vulns
medium 5.5

CVE-2021-20284 json

A flaw was found in GNU Binutils 2.35.1, where there is a heap-based buffer overflow in _bfd_elf_slurp_secondary_reloc_section in elf.c due…

published 2021-03-26 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7712

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 70%
public exploits
0
none known

Summary

A flaw was found in GNU Binutils 2.35.1, where there is a heap-based buffer overflow in _bfd_elf_slurp_secondary_reloc_section in elf.c due to the number of symbols not calculated correctly. The highest threat from this vulnerability is to system availability.

Patch / fix

  • binutils Debian 14, Debian 13, Debian 12 2.37-3

debian advisories DEBIAN-CVE-2021-20284

  • binutils RHEL 8 2.30-108.el8

red hat advisories RHSA-2021:4364

  • binutils SLES for SAP 15, SLES 15-LTSS, SLE High Performance Computing 15-LTSS +1 more 2.37-6.23.1
  • binutils SLES for SAP 15 SP1, SLES 15 SP1-LTSS, SLES 15 SP1-BCL +9 more 2.37-7.21.2
  • bpftrace SLE Module for Development Tools 15 SP3 0.11.4-3.2.1
  • binutils SLES for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +11 more 2.37-9.39.1
  • cross-ppc-binutils SLE Software Development Kit 12 SP5 2.37-9.39.1
  • cross-spu-binutils SLE Software Development Kit 12 SP5 2.37-9.39.1

suse advisories SUSE-SU-2022:0934-1SUSE-SU-2021:3616-1SUSE-SU-2021:3593-1

  • binutils openSUSE Tumbleweed 2.37-1.3
  • binutils openSUSE Leap 15.2 2.37-lp152.4.9.1
  • bpftrace openSUSE Leap 15.2 0.11.4-lp152.2.7.1
  • cross-rx-binutils openSUSE Leap 15.2 2.37-lp152.4.9.1
  • cross-arm-binutils openSUSE Leap 15.2 2.37-lp152.4.9.1
  • cross-avr-binutils openSUSE Leap 15.2 2.37-lp152.4.9.1
  • cross-ppc-binutils openSUSE Leap 15.2 2.37-lp152.4.9.1
  • cross-spu-binutils openSUSE Leap 15.2 2.37-lp152.4.9.1

opensuse advisories openSUSE-SU-2024:10651-1openSUSE-SU-2021:1475-1openSUSE-SU-2021:3616-1

  • binutils Rocky Linux 8 2.30-108.el8

rocky linux advisories RLSA-2021:4364

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-2021-20284 updated cvss 4.7

binutils: Heap-based buffer overflow in _bfd_elf_slurp_secondary_reloc_section in elf.c

  • Red Hat Enterprise Linux 8 gcc-toolset-10-binutils
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 8) binutils-devel 2.30-108.el8, binutils-debuginfo 2.30-108.el8, binutils-debugsource 2.30-108.el8 Red Hat Enterprise Linux BaseOS (v. 8) binutils 2.30-108.el8
    fixed: vendor fix RHSA-2021:4364
  • Red Hat Enterprise Linux 6 binutils Red Hat Enterprise Linux 7 binutils Red Hat Enterprise Linux 8 gcc-toolset-9-binutils Red Hat Enterprise Linux 9 binutils, binutils-gold
    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

Exploit prediction

1.29% chance of exploitation in the next 30 days, higher than 70% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=26931 referenced PoC, tagged "exploit" by a source, unverified
  • bugzilla.redhat.com https://bugzilla.redhat.com/show_bug.cgi?id=1937784 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • n/a binutils

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.