# CVE-2021-42379: busybox: A use-after-free in Busybox's awk applet leads to denial of service and possibly code execution when processing a cra...

CVE-2021-42379 is fixed in 6 products on 1 platform, first by busybox 1:1.27.2-2ubuntu3.4, released November 15, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-42379
- Priority: High
- CVSS: 7.2 (high)
- EPSS: 0.0280
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Nov 15, 2021

## Description

A use-after-free in Busybox's awk applet leads to denial of service and possibly code execution when processing a crafted awk pattern in the next_input_file function

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | busybox Debian 12.15 (bookworm) | 1:1.35.0-1 | [DEBIAN-CVE-2021-42379](https://patchblox.com/security/data/fix/linux/debian-cve-2021-42379.md) | Nov 15, 2021 |
| Linux | busybox Debian 13.5 (trixie) | 1:1.35.0-1 | [DEBIAN-CVE-2021-42379](https://patchblox.com/security/data/fix/linux/debian-cve-2021-42379.md) | Nov 15, 2021 |
| Linux | busybox Debian 14 | 1:1.35.0-1 | [DEBIAN-CVE-2021-42379](https://patchblox.com/security/data/fix/linux/debian-cve-2021-42379.md) | Nov 15, 2021 |
| Linux | busybox Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [busybox 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-busybox-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | busybox Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [busybox 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-busybox-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | busybox Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [busybox 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-busybox-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |
| Linux | busybox-initramfs Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [busybox-initramfs 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-busybox-initramfs-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | busybox-initramfs Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [busybox-initramfs 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-busybox-initramfs-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | busybox-initramfs Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [busybox-initramfs 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-busybox-initramfs-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |
| Linux | busybox-static Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [busybox-static 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-busybox-static-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | busybox-static Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [busybox-static 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-busybox-static-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | busybox-static Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [busybox-static 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-busybox-static-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |
| Linux | busybox-syslogd Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [busybox-syslogd 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-busybox-syslogd-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | busybox-syslogd Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [busybox-syslogd 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-busybox-syslogd-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | busybox-syslogd Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [busybox-syslogd 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-busybox-syslogd-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |
| Linux | udhcpc Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [udhcpc 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-udhcpc-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | udhcpc Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [udhcpc 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-udhcpc-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | udhcpc Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [udhcpc 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-udhcpc-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |
| Linux | udhcpd Ubuntu 18.04.6 LTS (bionic) | 1:1.27.2-2ubuntu3.4 | [udhcpd 1:1.27.2-2ubuntu3.4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-udhcpd-1-1.27.2-2ubuntu3.4.md) | Nov 15, 2021 |
| Linux | udhcpd Ubuntu 20.04 LTS (focal) | 1:1.30.1-4ubuntu6.4 | [udhcpd 1:1.30.1-4ubuntu6.4](https://patchblox.com/security/data/fix/linux/ubuntu-focal-udhcpd-1-1.30.1-4ubuntu6.4.md) | Nov 15, 2021 |
| Linux | udhcpd Ubuntu 22.04.1 LTS (jammy) | 1:1.30.1-7ubuntu2 | [udhcpd 1:1.30.1-7ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-udhcpd-1-1.30.1-7ubuntu2.md) | Nov 15, 2021 |

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