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CVE-2018-1061· NVD / CVE Program· CNA redhat

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.IS_LINE_JUNK me

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 4.9% (FIRST EPSS); higher than 92% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: python2 (Alpine:v3.10) 2.7.15-r0; python3 (Alpine:v3.5) 3.5.6-r0; python3 (Alpine:v3.6) 3.6.5-r0.

Low priority for now. Upgrade to python2 (Alpine:v3.10) 2.7.15-r0; python3 (Alpine:v3.5) 3.5.6-r0; python3 (Alpine:v3.6) 3.6.5-r0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.IS_LINE_JUNK method. An attacker could use this flaw to cause denial of service.

HighCVSS 7.5 · v3.0—No exploit Fix available
Published
Jun 19, 2018
Updated
Oct 15, 2026
EPSS
4.9% · 92th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 4.9%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.5
CNA · redhat
6.5
1.0 point gap

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2018-1061

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
pythonpython
debiandebian linux
redhatansible tower
redhatenterprise linux desktop
redhatenterprise linux server
redhatenterprise linux workstation
canonicalubuntu linux
fedoraprojectfedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux12.04
  • canonical ubuntu linux14.04
  • canonical ubuntu linux16.04
  • canonical ubuntu linux18.04
  • debian debian linux8.0
  • debian debian linux9.0
  • fedoraproject fedora28
  • fedoraproject fedora29
  • fedoraproject fedora30
  • python pythonbefore 2.7.15
  • python python3.0 and later · before 3.4.9
  • python python3.5.0 and later · up to 3.5.5 inclusive
  • python python3.6 and later · up to 3.6.4 inclusive
  • python python3.7.0
  • redhat ansible tower3.3
  • redhat enterprise linux desktop7.0
  • redhat enterprise linux server7.0
  • redhat enterprise linux workstation7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (redhat). Independent of NVD's CPE analysis and usually ahead of it.

  • [UNKNOWN] python

    • python 2.7.15, python 3.4.9, python 3.5.6, python 3.7.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.10python2before 2.7.15-r02.7.15-r0
Alpine:v3.5python3before 3.5.6-r03.5.6-r0
Alpine:v3.6python3before 3.6.5-r03.6.5-r0
Alpine:v3.8python3before 3.6.6-r03.6.6-r0
Debian:11python2.7before 2.7.14-72.7.14-7
Debian:8python2.7before 2.7.9-2+deb8u22.7.9-2+deb8u2
Debian:8python3.4before 3.4.2-1+deb8u13.4.2-1+deb8u1
Debian:9python2.7before 2.7.13-2+deb9u32.7.13-2+deb9u3
Debian:9python3.5before 3.5.3-1+deb9u13.5.3-1+deb9u1
openSUSE:Leap 15.1python3before 3.6.10-lp151.6.7.13.6.10-lp151.6.7.1
openSUSE:Leap 15.1python3-basebefore 3.6.10-lp151.6.7.13.6.10-lp151.6.7.1
openSUSE:Tumbleweedpython36before 3.6.15-1.13.6.15-1.1
Red Hat:enterprise_linux:7::clientpythonbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-debugbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-debuginfobefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-develbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-libsbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-testbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clientpython-toolsbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:enterprise_linux:7::clienttkinterbefore 0:2.7.5-76.el70:2.7.5-76.el7
Red Hat:rhel_aus:7.4::serverpythonbefore 0:2.7.5-63.el7_40:2.7.5-63.el7_4
Red Hat:rhel_aus:7.4::serverpython-debugbefore 0:2.7.5-63.el7_40:2.7.5-63.el7_4
Red Hat:rhel_aus:7.4::serverpython-debuginfobefore 0:2.7.5-63.el7_40:2.7.5-63.el7_4
Red Hat:rhel_aus:7.4::serverpython-develbefore 0:2.7.5-63.el7_40:2.7.5-63.el7_4

+56

Same product

python: all records

Other highest-scoring records for the same primary product.

  • CVE-2016-5636Integer overflow in the get_data function in zipimport.c in CPython (aka Python) before 2.7.12, 3.x before 3.4.5, and 3.5.x before 3.5.2 all
    47Plan
  • CVE-2007-4559Directory traversal vulnerability in the (1) extract and (2) extractall functions in the tarfile module in Python allows user-assisted remot
    47Plan
  • CVE-2021-3177Python 3.x through 3.9.1 has a buffer overflow in PyCArg_repr in _ctypes/callproc.c, which may lead to remote code execution in certain Pyth
    46Plan
  • CVE-2014-4650The CGIHTTPServer module in Python 2.7.5 and 3.3.4 does not properly handle URLs in which URL encoding is used for path separators, which al
    46Plan
  • CVE-2018-1000802Python Software Foundation Python (CPython) version 2.7 contains a CWE-77: Improper Neutralization of Special Elements used in a Command ('C
    45Plan
  • CVE-2020-27619In Python 3 through 3.9.0, the Lib/test/multibytecodec_support.py CJK codec tests call eval() on content retrieved via HTTP.
    42Plan

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:python22.7.15-r0 · Alpine:v3.10Package registry (OSV)
alpine:python33.5.6-r0 · Alpine:v3.5Package registry (OSV)
debian:python2.72.7.14-7 · Debian:11Package registry (OSV)
debian:python3.43.4.2-1+deb8u1 · Debian:8Package registry (OSV)
debian:python3.53.5.3-1+deb9u1 · Debian:9Package registry (OSV)
opensuse:python33.6.10-lp151.6.7.1 · openSUSE:Leap 15.1Package registry (OSV)
opensuse:python3-base3.6.10-lp151.6.7.1 · openSUSE:Leap 15.1Package registry (OSV)
opensuse:python363.6.15-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:python0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-debug0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-debuginfo0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-devel0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-libs0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-test0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python-tools0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:python27-python0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6Package registry (OSV)
red hat:python27-python-debug0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6Package registry (OSV)
red hat:python27-python-debuginfo0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6Package registry (OSV)
red hat:python27-python-devel0:2.7.16-4.el6 · Red Hat:rhel_software_collections:3::el6Package registry (OSV)
red hat:tkinter0:2.7.5-76.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
suse:python2.6.9-40.15.1 · SUSE:Linux Enterprise Software Development Kit 11 SP4Package registry (OSV)
suse:python-base2.6.9-40.15.1 · SUSE:Linux Enterprise Software Development Kit 11 SP4Package registry (OSV)
suse:python-doc2.6-8.40.15.1 · SUSE:Linux Enterprise Software Development Kit 11 SP4Package registry (OSV)
suse:python33.4.6-25.16.1 · SUSE:Linux Enterprise Desktop 12 SP3Package registry (OSV)
suse:python3-base3.4.6-25.16.1 · SUSE:Linux Enterprise Desktop 12 SP3Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records