CVE-2019-18348

Name: CVE-2019-18348
Creator: NVD / NIST
Published: 2019-10-23T17:15:12.973+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 3.51%

Last modified Jun 17, 2026

CVE-2019-18348 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. An issue was discovered in urllib2 in Python 2.x through 2.7.17 and urllib in Python 3.x through 3.8.0. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n (specifically in the host component of a URL) followed by an HTTP header. EPSS estimates a 3.51% chance of exploitation in the next 30 days.

Description

An issue was discovered in urllib2 in Python 2.x through 2.7.17 and urllib in Python 3.x through 3.8.0. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n (specifically in the host component of a URL) followed by an HTTP header. This is similar to the CVE-2019-9740 query string issue and the CVE-2019-9947 path string issue. (This is not exploitable when glibc has CVE-2016-10739 fixed.). This is fixed in: v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1; v3.6.11, v3.6.11rc1, v3.6.12; v3.7.8, v3.7.8rc1, v3.7.9; v3.8.3, v3.8.3rc1, v3.8.4, v3.8.4rc1, v3.8.5, v3.8.6, v3.8.6rc1.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

3.51%

87.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-74

Affected Software

Vendor	Product	Versions
Python	Python	>= 2.0, <= 2.7.17
Python	Python	>= 3.0, < 3.5.10
Python	Python	>= 3.6.0, < 3.6.11
Python	Python	>= 3.7.0, < 3.7.8
Python	Python	>= 3.8.0, < 3.8.3

References

http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00041.htmlMailing List, Technical Description
https://bugs.python.org/issue30458#msg347282Issue Tracking, Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1727276Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.htmlMailing List, Technical Description
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A5NSAX4SC3V64PGZUPH7PRDLSON34Q5A/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M34WOYCDKTDE5KLUACE2YIEH7D37KHRX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UESGYI5XDAHJBATEZN3MHNDUBDH47AS6/
https://security.netapp.com/advisory/ntap-20191107-0004/Technical Description
https://usn.ubuntu.com/4333-1/Technical Description
https://usn.ubuntu.com/4333-2/Technical Description
https://www.oracle.com/security-alerts/cpuoct2020.htmlTechnical Description
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00041.htmlMailing List, Technical Description
https://bugs.python.org/issue30458#msg347282Issue Tracking, Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1727276Issue Tracking, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.htmlMailing List, Technical Description
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A5NSAX4SC3V64PGZUPH7PRDLSON34Q5A/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M34WOYCDKTDE5KLUACE2YIEH7D37KHRX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UESGYI5XDAHJBATEZN3MHNDUBDH47AS6/
https://security.netapp.com/advisory/ntap-20191107-0004/Technical Description
https://usn.ubuntu.com/4333-1/Technical Description
https://usn.ubuntu.com/4333-2/Technical Description
https://www.oracle.com/security-alerts/cpuoct2020.htmlTechnical Description

Timeline

Published: Oct 23, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-18348?

How severe is CVE-2019-18348?

CVE-2019-18348 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 3.51% probability of exploitation in the next 30 days.

How do I fix CVE-2019-18348?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-18348?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST