Security readout for executives and security teams
Plain-English summary
CVE-2021-42383 is a memory safety flaw in BusyBox awk. If a system processes a crafted awk pattern, BusyBox can crash and may allow code execution. The main risk is embedded Linux, appliances, containers, or firmware images that include BusyBox awk and accept attacker-controlled patterns.
Executive priority
Treat this as a high-priority hygiene and exposure-management issue, especially for embedded systems and appliances. It is not KEV-listed in the provided bundle, so urgency should be driven by asset exposure and whether untrusted awk pattern processing exists.
Technical view
The issue is a use-after-free in BusyBox's awk applet, specifically described in the evaluate function while processing a crafted awk pattern. The CVSS 3.1 score is 7.2 with network attack vector, high privileges required, no user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely where BusyBox includes the awk applet and processes untrusted or indirectly controlled awk patterns. BusyBox is common in embedded systems and minimal Linux environments, but the source bundle does not identify exact affected versions.
Exploitation context
The bundle does not show CISA KEV status or cited evidence of active exploitation. Exploitability depends on whether an attacker can influence awk pattern processing; the CVSS vector indicates high privileges are required.
Researcher notes
Evidence is incomplete on exact affected BusyBox versions in the bundle. The most defensible validation path is asset discovery, awk applet presence, input-flow review, and vendor advisory matching. Avoid assuming remote unauthenticated exploitation from the CVSS vector alone.
Mitigation direction
- Inventory BusyBox use across firmware, appliances, containers, and minimal Linux hosts.
- Apply vendor-provided BusyBox or platform updates from applicable advisories.
- Restrict BusyBox awk from processing untrusted patterns where feasible.
- Check NetApp, Fedora, OS, and appliance vendor guidance for affected builds.
- Replace vulnerable images or firmware when vendor fixes are available.
Validation and detection
- Confirm whether BusyBox awk is present in deployed systems or images.
- Identify workflows that pass user-controlled input into BusyBox awk patterns.
- Compare installed packages or firmware against vendor advisory fixed versions.
- Prioritize internet-facing, appliance, and embedded deployments for review.
- Track remediation evidence for each affected asset or image lineage.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-42383 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.2 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H1.25.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.2HighVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://jfrog.com/blog/unboxing-busybox-14-new-vulnerabilities-uncovered-by-claroty-and-jfrog/CVE reference
- FEDORA-2021-5a95823596CVE reference · vendor-advisory
- FEDORA-2021-c52c0fe490CVE reference · vendor-advisory
- https://security.netapp.com/advisory/ntap-20211223-0002/CVE reference
- https://claroty.com/team82/research/unboxing-busybox-14-vulnerabilities-uncovered-by-claroty-jfrogCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.