CVE-2018-1061: Input Validation

Published Feb 26, 2018
·
Updated

Catastrophic backtracking vulnerability was found in Python. Exploitation of a regular expression in difflib.ISLINEJUNK method in servers that use difflib can lead to denial of service.

Upstream issue:

https://bugs.python.org/issue32981

Other sources

python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.ISLINEJUNK method. An attacker could use this flaw to cause denial of service.

Launchpad

Affected Software

32 affected componentsFixes available
redhat/python<2.7.15
2.7.15
redhat/python<3.4.9
3.4.9
redhat/python<3.5.6
3.5.6
redhat/python<3.7.0
3.7.0
debian/python2.7
2.7.18-8+deb11u1
Python Python<2.7.15
Python Python>=3.0<3.4.9
Python Python>=3.5.0<=3.5.5
Python Python>=3.6<=3.6.4
Python Python=3.7.0-alpha1
Python Python=3.7.0-alpha2
Python Python=3.7.0-alpha3
Python Python=3.7.0-alpha4
Python Python=3.7.0-beta1
Python Python=3.7.0-beta2
Python Python=3.7.0-beta3
Python Python=3.7.0-beta4
Python Python=3.7.0-beta5
Python Python=3.7.0-rc1
Debian Debian Linux=8.0
Debian Debian Linux=9.0
redhat Ansible Tower=3.3
redhat Enterprise Linux Desktop=7.0
redhat Enterprise Linux Server=7.0
redhat Enterprise Linux Workstation=7.0
Canonical Ubuntu Linux=12.04
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Fedoraproject Fedora=28
Fedoraproject Fedora=29
Fedoraproject Fedora=30

Event History

Jun 19, 2018
CVE Published
via MITRE·12:00 PM
Data Sourced
via MITRE·12:00 PM
DescriptionSeverityWeakness
Feb 20, 2026
Data Sourced
via Ubuntu·03:18 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·03:19 PM
Description
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Frequently Asked Questions

1

What is the severity of CVE-2018-1061?

CVE-2018-1061 is classified as a denial of service vulnerability due to catastrophic backtracking in regular expressions.

2

How do I fix CVE-2018-1061?

To fix CVE-2018-1061, upgrade to Python versions 2.7.18 or higher, 3.4.10 or higher, 3.5.7 or higher, or 3.7.1 or higher.

3

What versions of Python are affected by CVE-2018-1061?

CVE-2018-1061 affects Python versions up to and including 2.7.15, 3.4.9, 3.5.6, and 3.7.0.

4

What impact does CVE-2018-1061 have on servers?

Exploitation of CVE-2018-1061 can lead to denial of service on servers using the difflib.IS_LINE_JUNK method.

5

Are there any known exploits for CVE-2018-1061?

As of now, there are no public details about known exploits targeting CVE-2018-1061.

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