# CVE-2019-20637: varnish: Varnish Cache is a high-performance HTTP accelerator

CVE-2019-20637 is fixed in 6 products on 1 platform, first by RHSA-2020:4756, released November 4, 2020. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2019-20637
- Priority: High
- CVSS: 7.5 (Moderate)
- EPSS: 0.0179
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 8, 2020

## Description

Varnish Cache is a high-performance HTTP accelerator. It stores web pages in memory so web servers don't have to create the same web page over and over again, giving the website a significant speed up.  The following packages have been upgraded to a later upstream version: varnish (6.0.6). (BZ#1795673)  Security Fix(es):  * varnish: denial of service handling certain crafted HTTP/1 requests (CVE-2019-15892)  * varnish: remote clients may cause Varnish to assert and restart which could result in DoS (CVE-2020-11653)  * varnish: not clearing pointer between two client requests leads to information disclosure (CVE-2019-20637)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.  Additional Changes:  For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.3 Release Notes linked from the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libvarnishapi1 Ubuntu 18.04.6 LTS (bionic) | 5.2.1-1ubuntu0.1 | [libvarnishapi1 5.2.1-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libvarnishapi1-5.2.1-1ubuntu0.1.md) | Jan 25, 2022 |
| Linux | libvarnishapi2 Ubuntu 20.04 LTS (focal) | 6.2.1-2ubuntu0.1 | [libvarnishapi2 6.2.1-2ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libvarnishapi2-6.2.1-2ubuntu0.1.md) | Jan 25, 2022 |
| Linux | varnish RHEL 8 | 0:6.0.6-2.module+el8.3.0+6843+b3b42fcc | [RHSA-2020:4756](https://patchblox.com/security/data/fix/linux/rhsa-2020-4756.md) | Nov 4, 2020 |
| Linux | varnish Ubuntu 18.04.6 LTS (bionic) | 5.2.1-1ubuntu0.1 | [varnish 5.2.1-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-varnish-5.2.1-1ubuntu0.1.md) | Jan 25, 2022 |
| Linux | varnish Ubuntu 20.04 LTS (focal) | 6.2.1-2ubuntu0.1 | [varnish 6.2.1-2ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-varnish-6.2.1-2ubuntu0.1.md) | Jan 25, 2022 |
| Linux | varnish ol 8 | 0:6.0.6-2.module+el8.3.0+7653+45014445 | [ELSA-2020-4756](https://patchblox.com/security/data/fix/linux/elsa-2020-4756.md) | Nov 10, 2020 |
| Linux | varnish-devel RHEL 8 | 0:6.0.6-2.module+el8.3.0+6843+b3b42fcc | [RHSA-2020:4756](https://patchblox.com/security/data/fix/linux/rhsa-2020-4756.md) | Nov 4, 2020 |
| Linux | varnish-devel ol 8 | 0:6.0.6-2.module+el8.3.0+7653+45014445 | [ELSA-2020-4756](https://patchblox.com/security/data/fix/linux/elsa-2020-4756.md) | Nov 10, 2020 |
| Linux | varnish-docs RHEL 8 | 0:6.0.6-2.module+el8.3.0+6843+b3b42fcc | [RHSA-2020:4756](https://patchblox.com/security/data/fix/linux/rhsa-2020-4756.md) | Nov 4, 2020 |
| Linux | varnish-docs ol 8 | 0:6.0.6-2.module+el8.3.0+7653+45014445 | [ELSA-2020-4756](https://patchblox.com/security/data/fix/linux/elsa-2020-4756.md) | Nov 10, 2020 |
| Linux | varnish-modules RHEL 8 | 0:0.15.0-5.module+el8.3.0+6843+b3b42fcc | [RHSA-2020:4756](https://patchblox.com/security/data/fix/linux/rhsa-2020-4756.md) | Nov 4, 2020 |
| Linux | varnish-modules ol 8 | 0:0.15.0-5.module+el8.3.0+7653+45014445 | [ELSA-2020-4756](https://patchblox.com/security/data/fix/linux/elsa-2020-4756.md) | Nov 10, 2020 |

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