Security readout for executives and security teams
Plain-English summary
BusyBox is embedded in many Linux-based products. CVE-2021-42385 affects its awk applet: a crafted awk pattern can trigger a use-after-free, causing denial of service and possibly code execution. Business urgency is highest where BusyBox awk processes untrusted or remotely supplied input.
Executive priority
Treat as a high-priority inventory and patching issue for embedded, appliance, and Linux fleet owners. It is not cited as actively exploited in the provided sources, but possible code execution and broad BusyBox deployment justify focused remediation where untrusted input can reach awk.
Technical view
The CVE describes CWE-416 use-after-free in BusyBox awk's evaluate function while processing a crafted awk pattern. The supplied CVSS 3.1 score is 7.2 high, with network attack vector, low complexity, high privileges required, no user interaction, and high confidentiality, integrity, and availability impacts.
Likely exposure
Exposure is likely in embedded Linux, appliances, containers, and distributions bundling BusyBox. The bundle does not enumerate exact vulnerable versions, so teams must validate by package inventory and vendor advisories, including Fedora, Debian LTS, NetApp, BusyBox, and device vendors.
Exploitation context
The bundle does not show CISA KEV listing or cited active exploitation. The described trigger is crafted awk input, so practical risk depends on whether attackers can influence awk patterns processed by BusyBox in a product, script, service, or administrative workflow.
Researcher notes
Key uncertainty is version and product scope: the provided CVE bundle lists BusyBox generically with unspecified versions. Research should map downstream packages, firmware builds, and vendor advisories before declaring exposure. Avoid assuming exploitation beyond the crafted-pattern vulnerability described by CVE, JFrog, and Claroty.
Mitigation direction
- Inventory systems and products that include BusyBox or BusyBox awk.
- Apply vendor or distribution BusyBox updates where advisories are available.
- Check appliance vendors for product-specific fixes, workarounds, or exposure statements.
- Avoid processing untrusted awk patterns with BusyBox awk until remediated.
- Track Debian, Fedora, NetApp, BusyBox, and device-vendor guidance for version applicability.
Validation and detection
- Confirm BusyBox presence and version from package manifests or firmware SBOMs.
- Identify scripts, services, or admin tools invoking BusyBox awk.
- Determine whether external users can influence awk patterns or processed input.
- Compare installed packages against Fedora, Debian LTS, NetApp, and vendor advisories.
- Prioritize internet-facing or multi-tenant systems where awk input is attacker-influenced.
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-2021-42385 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
- https://lists.debian.org/debian-lts-announce/2025/01/msg00012.htmlCVE 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.