CVE-2013-4238

MEDIUMCVSS v2 · 4.34.3—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 4.3 — v2 rates that MEDIUM (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:M/Au:N/C:N/I:P/A:N. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 5.3% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 5%CVSS v2: 4.3Exploit: None knownExposed: 0

A fix is available — apply it.

The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

CVSS v2.0 (legacy)
4.3MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
4.3(low)
EG Risk
26(Track)
EG Risk 26/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity43% × 45%
Exploitation5% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
5%
EPSS %ILE
92%
KEV
Not listed

Published

August 18, 2013

Last Modified

April 29, 2026

References (30)

Vendor Advisories for CVE-2013-4238(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupython3.3-minimal (3.3.1-1ubuntu5.2) @ raring2026-05-28ubuntu
ubuntupython3.2-minimal (3.2.3-6ubuntu3.4) @ quantal2026-05-28ubuntu
ubuntupython2.7-minimal (2.7.3-5ubuntu4.3) @ quantal2026-05-28ubuntu
ubuntupython2.6-minimal (2.6.5-1ubuntu6.2) @ lucid2026-05-28ubuntu
redhatrhev-hypervisor6-0:6.5-20131115.0.3.2.el6_52013-11-21redhat
redhatpython-0:2.6.6-51.el62013-11-20redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
python2.7—2.7.5-8—
Debian:6.0(1)
PackageVulnerable rangeFixed inDependents
python2.62.6.6-82.6.6-8+deb6u1—
Debian:7(1)
PackageVulnerable rangeFixed inDependents
python2.72.7.3-6, 2.7.3-6+deb7u12.7.3-6+deb7u2—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(5)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 5× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 119 total refreshes for this CVE.

  1. 2026-08-21 23:44 UTCEPSS rescore
  2. 2026-08-20 22:50 UTCEPSS rescore
  3. 2026-08-19 16:59 UTCEPSS rescore
  4. 2026-08-18 13:42 UTCEPSS rescore
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  9. 2026-08-08 16:31 UTCEPSS rescore
  10. 2026-08-07 18:26 UTCOSV refresh
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  18. 2026-07-26 13:48 UTCEG score recompute▲ 4.30
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  21. 2026-07-23 01:10 UTCEG score recompute
  22. 2026-07-23 00:13 UTCEG score recompute
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  24. 2026-07-22 14:04 UTCEPSS rescore
  25. 2026-07-22 14:04 UTCEPSS rescore
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  1. 2026-07-22 11:18 UTCOSV refresh
  2. 2026-07-21 15:21 UTCEPSS rescore
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  5. 2026-07-19 14:27 UTCEPSS rescore
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  19. 2026-07-06 02:19 UTCEPSS rescore
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  21. 2026-07-05 06:21 UTCOSV refresh
  22. 2026-07-05 02:26 UTCEPSS rescore
  23. 2026-07-04 06:27 UTCEPSS rescore
  24. 2026-07-01 15:02 UTCEPSS rescore
  25. 2026-06-30 23:19 UTCEPSS rescore
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  27. 2026-06-28 14:03 UTCEPSS rescore
  28. 2026-06-28 04:53 UTCEPSS rescore
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  30. 2026-06-27 03:05 UTCEPSS rescore
  31. 2026-06-25 13:46 UTCEPSS rescore
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  40. 2026-06-18 17:49 UTCEPSS rescore
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  44. 2026-06-16 17:49 UTCEPSS rescore
  45. 2026-06-16 17:49 UTCEPSS rescore
  46. 2026-06-16 17:44 UTCOSV refresh
  47. 2026-06-15 17:44 UTCEPSS rescore
  48. 2026-06-14 23:14 UTCEPSS rescore
  49. 2026-06-13 22:57 UTCEPSS rescore
  50. 2026-06-12 23:08 UTCEPSS rescore
  51. 2026-06-11 13:56 UTCEPSS rescore
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  55. 2026-06-06 13:45 UTCEPSS rescore
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  69. 2026-05-29 13:41 UTCEPSS rescore
  70. 2026-05-29 13:41 UTCEPSS rescore
  71. 2026-05-28 22:57 UTCEG score recompute
  72. 2026-05-28 22:57 UTCVendor advisory
  73. 2026-05-28 22:56 UTCGHSA enrichment
  74. 2026-05-28 13:42 UTCEPSS rescore
  75. 2026-05-28 13:42 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(4)

What is CVE-2013-4238?
CVE-2013-4238 is a medium vulnerability published on August 18, 2013. The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate…
When was CVE-2013-4238 disclosed?
CVE-2013-4238 was first published in the National Vulnerability Database on August 18, 2013, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2013-4238 actively exploited?
CVE-2013-4238 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5% probability of exploitation in the next 30 days, which ranks it in the top 8.0% of all scored CVEs.
How do I remediate CVE-2013-4238?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2013-4238, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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