CVE-2021-4021: A vulnerability was found in Radare2 in versions prior to 5.6.2, 5.6.0, 5.5.4 and 5.5.2.
Noroxi assessment
Priority: Monitor (action score 30/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 65.3% of all records.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- Fixed version: radare2 (Alpine:v3.18) 5.5.2-r0.
Low priority for now. Upgrade to radare2 (Alpine:v3.18) 5.5.2-r0 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
A vulnerability was found in Radare2 in versions prior to 5.6.2, 5.6.0, 5.5.4 and 5.5.2. Mapping a huge section filled with zeros of an ELF64 binary for MIPS architecture can lead to uncontrolled resource consumption and DoS.
- Published
- Feb 24, 2022
- Updated
- Jun 17, 2026
- EPSS
- 1.0% · 65th percentile
- CWE
- CWE-400
Report tools
Action score
30
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| radare | radare2 | cpe:2.3:a:radare:radare2 |
Versions reported by the vendor
Affected version ranges reported by the assigning authority (fedora). Independent of NVD's CPE analysis and usually ahead of it.
n/a radare2
- radare2 5.6.2, radare2 5.6.0, radare2 5.5.4 and radare2 5.5.2affected
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- radare radare2up to 5.5.0 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.18 | radare2 | before 5.5.2-r0 | 5.5.2-r0 |
Same product
radare: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-1864Buffer Overflow and Potential Code Execution in Radare240Plan
- CVE-2025-1744Out-of-bounds Write in radare240Plan
- CVE-2024-29646Buffer Overflow vulnerability in radarorg radare2 v.5.8.8 allows an attacker to execute arbitrary code via the name, type, or group fields.39Monitor
Published before and after this one in the same product
- ← EarlierCVE-2022-0476Feb 23, 2022 · Denial of Service in radareorg/radare222Monitor
- ← EarlierCVE-2022-0695Feb 24, 2022 · Denial of Service in radareorg/radare222Monitor
- Later →CVE-2022-0849Mar 5, 2022 · Use After Free in r_reg_get_name_idx in radareorg/radare222Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:radare2 | 5.5.2-r0 · Alpine:v3.18 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-400 · Uncontrolled Resource ConsumptionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Root cause
Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.
The bug in code
The whole CWE-400 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
function expand(node) {
return node.children.map(expand);
}Fixed
const MAX_DEPTH = 32;
function expand(node, depth = 0) {
if (depth > MAX_DEPTH) throw new Error("too deep");
return node.children.map((c) => expand(c, depth + 1));
}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Change log (1)
- Fix✗ → ✓
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