CVE-2021-42382 is a high-severity vulnerability identified in the BusyBox software suite, specifically within its awk applet. BusyBox is a widely used collection of Unix utilities often embedded in Linux-based systems, particularly in resource-constrained environments such as embedded devices, routers, and IoT devices. The vulnerability is classified as a use-after-free (CWE-416) in the getvar_s function, which is responsible for processing awk patterns. A use-after-free occurs when a program continues to use memory after it has been freed, leading to undefined behavior. In this case, processing a specially crafted awk pattern can trigger this flaw, resulting in a denial of service (DoS) due to application crashes or potentially enabling arbitrary code execution. The CVSS 3.1 base score for this vulnerability is 7.2, indicating a high severity level. The vector string (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) reveals that the attack can be performed remotely over the network with low attack complexity but requires high privileges (PR:H) and no user interaction. The impact affects confidentiality, integrity, and availability, suggesting that exploitation could lead to full system compromise. No known exploits are currently reported in the wild, and the affected versions are unspecified, implying that multiple or all versions of BusyBox's awk applet may be vulnerable. No official patches are linked in the provided data, so mitigation may require manual updates or workarounds. Given BusyBox's prevalence in embedded Linux systems, this vulnerability poses a significant risk to devices relying on it for command-line utilities, especially where awk scripts are processed or exposed to untrusted input.

For European organizations, the impact of CVE-2021-42382 can be substantial, particularly for sectors relying heavily on embedded Linux devices running BusyBox, such as telecommunications, industrial control systems, smart infrastructure, and IoT deployments. Exploitation could lead to denial of service, disrupting critical services and operational continuity. More critically, the possibility of arbitrary code execution elevates the risk to full system compromise, potentially allowing attackers to pivot within networks, exfiltrate sensitive data, or disrupt operations. This is especially concerning for organizations managing critical infrastructure or those under regulatory frameworks like GDPR, where data confidentiality and integrity are paramount. The requirement for high privileges to exploit the vulnerability somewhat limits the attack surface but does not eliminate risk, as privilege escalation or insider threats could facilitate exploitation. The lack of user interaction means automated attacks or worm-like propagation within networks are plausible once initial access is gained. The absence of known exploits in the wild currently reduces immediate threat levels but does not preclude future exploitation, emphasizing the need for proactive mitigation.

Identify and inventory all devices and systems running BusyBox, focusing on those utilizing the awk applet. Apply vendor-supplied patches or updates for BusyBox as soon as they become available; if no official patch exists, consider upgrading BusyBox to the latest stable version where this vulnerability is addressed. Implement strict input validation and sanitization for any awk patterns or scripts processed by BusyBox to prevent processing of maliciously crafted patterns. Restrict access to systems running BusyBox awk applet to trusted users and networks, minimizing exposure to untrusted inputs. Employ application whitelisting and behavior monitoring to detect anomalous execution patterns indicative of exploitation attempts. Use privilege separation and least privilege principles to limit the ability of attackers to gain the high privileges required for exploitation. Monitor logs and network traffic for unusual activity related to awk usage or BusyBox processes, enabling early detection of exploitation attempts. For embedded devices where BusyBox updates are challenging, consider network segmentation and compensating controls to isolate vulnerable devices.