CVE-2021-3673Public exploitNetwork attack vector

Denial of service via unchecked page-table reads

Published Aug 2, 2021 · Updated Aug 3, 2024

Denial of service in radareorg radare2 5.3.1 allows attackers to exhaust memory by supplying a crafted LE binary for analysis. Within r_bin_le_get_sections, the LE parser fails to check whether r_buf_read_at returns a complete page-table entry and continues processing malformed section metadata. Exploitation requires radare2 to analyze the crafted file; memory consumption can grow until the process is killed.

CVSS severity7.5
High
EPSS probability1.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in radareorg radare2 5.3.1 allows attackers to exhaust memory by supplying a crafted LE binary for analysis. Within r_bin_le_get_sections, the LE parser fails to check whether r_buf_read_at returns a complete page-table entry and continues processing malformed section metadata. Exploitation requires radare2 to analyze the crafted file; memory consumption can grow until the process is killed.

The record

CVE
CVE-2021-3673
Published
Aug 2, 2021
Updated
Aug 3, 2024
Vendor
radareorg
Product
radare2
Classifications
CWE-20, CWE-252, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 2, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Radare2 version 5.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

radareorg · radare2version=Radare2 version 5.3.1

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
CWE-252Unchecked Return Value
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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