How severe is CVE-2021-20294?

CVE-2021-20294 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20294 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20294?

CVE-2021-20294 affects Gnu Binutils. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20294?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-20294 published?

CVE-2021-20294 was published on 2021-04-29 and last updated on 2026-06-17.

CVE-2021-20294

CVE-2021-20294 is a high-severity vulnerability in Gnu Binutils with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 6.8
EPSS exploit prediction: 3% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Gnu Binutils
Published: 2021-04-29
Last modified: 2026-06-17

Description

A flaw was found in binutils readelf 2.35 program. An attacker who is able to convince a victim using readelf to read a crafted file could trigger a stack buffer overflow, out-of-bounds write of arbitrary data supplied by the attacker. The highest impact of this flaw is to confidentiality, integrity, and availability.

Frequently asked questions

What is CVE-2021-20294?: A flaw was found in binutils readelf 2.35 program. An attacker who is able to convince a victim using readelf to read a crafted file could trigger a stack buffer overflow, out-of-bounds write of arbitrary data supplied by the attacker. The highest impact of this flaw is to confidentiality, integrity, and availability.
How severe is CVE-2021-20294?: CVE-2021-20294 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20294 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20294?: CVE-2021-20294 affects Gnu Binutils. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20294?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-20294 published?: CVE-2021-20294 was published on 2021-04-29 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:gnu:binutils:*:*:*:*:*:*:*:*

More vulnerabilities in Gnu Binutils

CVE-2018-12699 — Critical (CVSS 9.8): finish_stab in stabs.c in GNU Binutils 2.30 allows attackers to cause a denial of service (heap-based buffer overflow)…
CVE-2017-7614 — Critical (CVSS 9.8): elflink.c in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils 2.28, has a "member…
CVE-2014-9939 — Critical (CVSS 9.8): ihex.c in GNU Binutils before 2.26 contains a stack buffer overflow when printing bad bytes in Intel Hex objects.
CVE-2017-7226 — Critical (CVSS 9.1): The pe_ILF_object_p function in the Binary File Descriptor (BFD) library (aka libbfd), as distributed in GNU Binutils…
CVE-2017-6969 — Critical (CVSS 9.1): readelf in GNU Binutils 2.28 is vulnerable to a heap-based buffer over-read while processing corrupt RL78 binaries. The…
CVE-2020-19726 — High (CVSS 8.8): An issue was discovered in binutils libbfd.c 2.36 relating to the auxiliary symbol data allows attackers to read or…

All CVEs affecting Gnu Binutils →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →