CVE-2021-20284

Exp

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.

Published: 2021-03-26 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-20284 is rated High Exploit Risk (61.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.29%). 2 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.20% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-20284

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-20284

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.09% 1.29% +1.20%
2 2025-11-21 0.24% 0.09% -0.15%
3 2025-11-18 — 0.24% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-20284

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-20284

OS Trackers for CVE-2021-20284

vendor priority summary link
debian unimportant CVE-2021-20284 unimportant priority: Debian including 1 source packages (binutils), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-20284
gentoo normal CVE-2021-20284: 1 GLSA(s) (202208-30), 2 atom(s) (sys-devel/binutils, sys-libs/binutils-libs); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2021-20284
redhat low — https://access.redhat.com/security/cve/CVE-2021-20284
suse medium CVE-2021-20284 severity moderate: SUSE including 441 source package names (0.23.1-12.3:binutils-2.37-7.21.2, 0.23.1-12.3:libctf-nobfd0-2.37-7.21.2, …), 1382 product×package rows across 316 product lines (Container bci/bci-sle15-kernel-module-devel, Container bci/gcc, … (316 product lines)): Fixed 1145, Known Affected 231, Known Not Affected 6. https://www.suse.com/security/cve/CVE-2021-20284/
ubuntu low CVE-2021-20284 low priority: Ubuntu including 1 source packages (binutils), 9 status rows across 9 suites (bionic, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): not-affected 7, ignored 1, released 1. https://ubuntu.com/security/CVE-2021-20284

Affected software / configurations for CVE-2021-20284

Vendor Product Version Raw CPE
gnu binutils 2.35.1 cpe:2.3:a:gnu:binutils:2.35.1:*:*:*:*:*:*:*
netapp cloud_backup — cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*
netapp ontap_select_deploy_administration_utility — cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:*

References for CVE-2021-20284

URL Tags
https://bugzilla.redhat.com/show_bug.cgi?id=1937784 Exploit Issue Tracking Third Party Advisory
https://security.gentoo.org/glsa/202208-30 Third Party Advisory
https://security.netapp.com/advisory/ntap-20210521-0010/ Third Party Advisory
https://sourceware.org/bugzilla/show_bug.cgi?id=26931 Exploit Issue Tracking Third Party Advisory
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