# CVE-2020-25681: dnsmasq: A flaw was found in dnsmasq before version 2.83

CVE-2020-25681 is fixed in 4 products on 1 platform, first by dnsmasq 2.79-1ubuntu0.2, released January 18, 2021. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2020-25681
- Priority: High
- CVSS: 8.1 (Medium)
- EPSS: 0.8409
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 18, 2021

## Description

A flaw was found in dnsmasq before version 2.83. A heap-based bufferoverflow was discovered in the way RRSets are sorted before validating withDNSSEC data. An attacker on the network, who can forge DNS replies such asthat they are accepted as valid, could use this flaw to cause a bufferoverflow with arbitrary data in a heap memory segment, possibly executingcode on the machine. The highest threat from this vulnerability is to dataconfidentiality and integrity as well as system availability.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dnsmasq RHEL 8 | 0:2.79-13.el8_3.1 | [RHSA-2021:0150](https://patchblox.com/security/data/fix/linux/rhsa-2021-0150.md) | Jan 19, 2021 |
| Linux | dnsmasq Ubuntu 18.04.6 LTS (bionic) | 2.79-1ubuntu0.2 | [dnsmasq 2.79-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-2.79-1ubuntu0.2.md) | Jan 18, 2021 |
| Linux | dnsmasq Ubuntu 20.04 LTS (focal) | 2.80-1.1ubuntu1.2 | [dnsmasq 2.80-1.1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-2.80-1.1ubuntu1.2.md) | Jan 18, 2021 |
| Linux | dnsmasq Ubuntu 24.10 (oracular) | 2.82-1ubuntu2 | [dnsmasq 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-dnsmasq-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq Ubuntu 25.04 (plucky) | 2.82-1ubuntu2 | [dnsmasq 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-plucky-dnsmasq-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq ol 8 | 0:2.79-13.el8_3.1 | [ELSA-2021-0150](https://patchblox.com/security/data/fix/linux/elsa-2021-0150.md) | Jan 20, 2021 |
| Linux | dnsmasq-base Ubuntu 18.04.6 LTS (bionic) | 2.79-1ubuntu0.2 | [dnsmasq-base 2.79-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-base-2.79-1ubuntu0.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-base Ubuntu 20.04 LTS (focal) | 2.80-1.1ubuntu1.2 | [dnsmasq-base 2.80-1.1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-base-2.80-1.1ubuntu1.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-base Ubuntu 24.10 (oracular) | 2.82-1ubuntu2 | [dnsmasq-base 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-dnsmasq-base-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-base Ubuntu 25.04 (plucky) | 2.82-1ubuntu2 | [dnsmasq-base 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-plucky-dnsmasq-base-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-base-lua Ubuntu 18.04.6 LTS (bionic) | 2.79-1ubuntu0.2 | [dnsmasq-base-lua 2.79-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-base-lua-2.79-1ubuntu0.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-base-lua Ubuntu 20.04 LTS (focal) | 2.80-1.1ubuntu1.2 | [dnsmasq-base-lua 2.80-1.1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-base-lua-2.80-1.1ubuntu1.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-base-lua Ubuntu 24.10 (oracular) | 2.82-1ubuntu2 | [dnsmasq-base-lua 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-dnsmasq-base-lua-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-base-lua Ubuntu 25.04 (plucky) | 2.82-1ubuntu2 | [dnsmasq-base-lua 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-plucky-dnsmasq-base-lua-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-utils RHEL 8 | 0:2.79-13.el8_3.1 | [RHSA-2021:0150](https://patchblox.com/security/data/fix/linux/rhsa-2021-0150.md) | Jan 19, 2021 |
| Linux | dnsmasq-utils Ubuntu 18.04.6 LTS (bionic) | 2.79-1ubuntu0.2 | [dnsmasq-utils 2.79-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-dnsmasq-utils-2.79-1ubuntu0.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-utils Ubuntu 20.04 LTS (focal) | 2.80-1.1ubuntu1.2 | [dnsmasq-utils 2.80-1.1ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-dnsmasq-utils-2.80-1.1ubuntu1.2.md) | Jan 18, 2021 |
| Linux | dnsmasq-utils Ubuntu 24.10 (oracular) | 2.82-1ubuntu2 | [dnsmasq-utils 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-dnsmasq-utils-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-utils Ubuntu 25.04 (plucky) | 2.82-1ubuntu2 | [dnsmasq-utils 2.82-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-plucky-dnsmasq-utils-2.82-1ubuntu2.md) | Jan 19, 2021 |
| Linux | dnsmasq-utils ol 8 | 0:2.79-13.el8_3.1 | [ELSA-2021-0150](https://patchblox.com/security/data/fix/linux/elsa-2021-0150.md) | Jan 20, 2021 |

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