CVE-2013-7440

CVE-2013-7440 is a medium-severity vulnerability in Python with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-19.

Key facts

• Severity: Medium (CVSS 3.x base score 5.9)
• CVSS v2: 4.3
• EPSS exploit prediction: 2% (78th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-19
• Affected product: Python
• Published: 2016-06-07
• Last modified: 2026-06-17

Description

The ssl.match_hostname function in CPython (aka Python) before 2.7.9 and 3.x before 3.3.3 does not properly handle wildcards in hostnames, which might allow man-in-the-middle attackers to spoof servers via a crafted certificate.

Frequently asked questions

What is CVE-2013-7440?

The ssl.match_hostname function in CPython (aka Python) before 2.7.9 and 3.x before 3.3.3 does not properly handle wildcards in hostnames, which might allow man-in-the-middle attackers to spoof servers via a crafted certificate.

How severe is CVE-2013-7440?

CVE-2013-7440 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2013-7440 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2013-7440?

CVE-2013-7440 primarily affects Python. In total, 26 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2013-7440?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2013-7440 published?

CVE-2013-7440 was published on 2016-06-07 and last updated on 2026-06-17.

References

• http://seclists.org/oss-sec/2015/q2/483
• http://seclists.org/oss-sec/2015/q2/523
• http://www.securityfocus.com/bid/74707
• https://access.redhat.com/errata/RHSA-2016:1166
• https://bugs.python.org/issue17997
• https://bugzilla.redhat.com/show_bug.cgi?id=1224999
• https://hg.python.org/cpython/rev/10d0edadbcdd

Affected products (26)

• cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.0:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.0.1:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.1:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.2:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.3:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.4:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.5:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.1.2150:*:*:*:*:*:x64:*
• cpe:2.3:a:python:python:3.2:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2:alpha:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.0:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.1:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.2:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.3:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.4:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.5:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.6:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.2.2150:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3:beta2:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3.0:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3.1:*:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3.1:rc1:*:*:*:*:*:*
• cpe:2.3:a:python:python:3.3.2:*:*:*:*:*:*:*

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Threat intelligence

Threat-intel indicators referencing this CVE:

• 203.192.232.180 (ipv4-addr)
• 177.53.215.134 (ipv4-addr)
• 5.99.196.202 (ipv4-addr)
• 121.164.135.251 (ipv4-addr)