How severe is CVE-2011-5240?

CVE-2011-5240 has a CVSS 2.0 base score of 5.8, rated medium severity.

Is CVE-2011-5240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2011-5240?

CVE-2011-5240 primarily affects Magentocommerce Magento. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2011-5240?

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

When was CVE-2011-5240 published?

CVE-2011-5240 was published on 2012-11-06 and last updated on 2026-06-16.

CVE-2011-5240

CVE-2011-5240 is a medium-severity vulnerability in Magentocommerce Magento with a CVSS 2.0 base score of 5.8. 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-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.8)
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Magentocommerce Magento
Published: 2012-11-06
Last modified: 2026-06-16

Description

Magento 1.5 and 1.6.2 does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.

Frequently asked questions

What is CVE-2011-5240?: Magento 1.5 and 1.6.2 does not verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via an arbitrary valid certificate.
How severe is CVE-2011-5240?: CVE-2011-5240 has a CVSS 2.0 base score of 5.8, rated medium severity.
Is CVE-2011-5240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2011-5240?: CVE-2011-5240 primarily affects Magentocommerce Magento. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2011-5240?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2011-5240 published?: CVE-2011-5240 was published on 2012-11-06 and last updated on 2026-06-16.

References

http://www.unrest.ca/peerjacking

Affected products (2)

cpe:2.3:a:magentocommerce:magento:1.5:*:*:*:*:*:*:*
cpe:2.3:a:magentocommerce:magento:1.6.2:*:*:*:*:*:*:*

More vulnerabilities in Magentocommerce Magento

CVE-2012-6091 — High (CVSS 7.5): Zend_XmlRpc Class in Magento before 1.7.0.2 contains an information disclosure vulnerability.

All CVEs affecting Magentocommerce Magento →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →