--- title: "CVE-2020-1935\n | Ubuntu" description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/CVE-2020-1935?format=md keywords: index, follow --- # CVE-2020-1935 Publication date 24 February 2020 Last updated 3 June 2026 --- Ubuntu priority **Low** [Why this priority?](https://ubuntu.com/security/cves/about#priority ) ## Cvss 3 Severity Score **4.8 · Medium** [Score breakdown](https://ubuntu.com/security/CVE-2020-1935?format=md#impact-score) Toggle side navigation ## Description In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely. [Read the notes from the security team](https://ubuntu.com/security/CVE-2020-1935?format=md#notes) ## Status Show unmaintained releases | Package | Ubuntu Release | Status | | --- | --- | --- | | tomcat7 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not in release | | 18.04 LTS bionic | Not affected | | 16.04 LTS xenial | Vulnerable | | 14.04 LTS trusty | Vulnerable | | tomcat8 | 26.04 LTS resolute | Not in release | | 25.10 questing | Not in release | | 25.04 plucky | Not in release | | 24.10 oracular | Not in release | | 24.04 LTS noble | Not in release | | 23.10 mantic | Not in release | | 23.04 lunar | Not in release | | 22.10 kinetic | Not in release | | 22.04 LTS jammy | Not in release | | 21.10 impish | Not in release | | 21.04 hirsute | Not in release | | 20.10 groovy | Not in release | | 20.04 LTS focal | Not in release | | 19.10 eoan | Not in release | | 18.04 LTS bionic | Vulnerable | | 16.04 LTS xenial | Fixed 8.0.32-1ubuntu1.13 | | 14.04 LTS trusty | Not in release | | tomcat9 | 26.04 LTS resolute | Not affected | | 25.10 questing | Not affected | | 25.04 plucky | Not affected | | 24.10 oracular | Not affected | | 24.04 LTS noble | Not affected | | 23.10 mantic | Not affected | | 23.04 lunar | Not affected | | 22.10 kinetic | Not affected | | 22.04 LTS jammy | Not affected | | 21.10 impish | Not affected | | 21.04 hirsute | Not affected | | 20.10 groovy | Not affected | | 20.04 LTS focal | Not affected | | 19.10 eoan | Ignored end of life | | 18.04 LTS bionic | Vulnerable | | 16.04 LTS xenial | Not in release | | 14.04 LTS trusty | Not in release | --- * [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) * [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses) * [Patch details](https://ubuntu.com/security/CVE-2020-1935?format=md#patch-details) ## Notes --- ### [ebarretto](https://launchpad.net/~ebarretto) bionic tomcat7 only builds libservlet3.0-java, not the Tomcat server binaries --- ### [mdeslaur](https://launchpad.net/~mdeslaur) backport to 8.0 available in 8.0.14-1+deb8u17 ### Patch details For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security) | Package | Patch details | | --- | --- | | tomcat7 | * Upstream: [702bf15](https://github.com/apache/tomcat/commit/702bf15bea292915684d931526d95d4990b2e73d) | | tomcat8 | * Upstream: [8fbe2e9](https://github.com/apache/tomcat/commit/8fbe2e962f0ea138d92361921643fe5abe0c4f56) | | tomcat9 | * Upstream: [8bfb0ff](https://github.com/apache/tomcat/commit/8bfb0ff7f25fe7555a5eb2f7984f73546c11aa26) | ## Severity score breakdown CVSS version: CVSS v3.0 **Base score** 4.8 · Medium * Base metrics | Parameter | Value | | --- | --- | | Attack vector | Network | | Attack complexity | High | | Privileges required | None | | User interaction | None | | Scope | Unchanged | | Confidentiality impact | Low | | Integrity impact | Low | | Availability impact | None | * Scores | Parameter | Value | | --- | --- | | Base score | 4.8 · Medium | | Exploitability score | - | | Impact score | - | **Vector:** CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N ## References * [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-1935) * [NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-1935) * [Launchpad](https://launchpad.net/bugs/cve/CVE-2020-1935) * [Debian](https://security-tracker.debian.org/tracker/CVE-2020-1935) ### Related Ubuntu Security Notices (USN) + [USN-4448-1](https://usn.ubuntu.com/USN-4448-1) + Tomcat vulnerabilities + 4 August 2020 ### Other references * *