What’s Vulnerable › Vulnerabilities

CVE-2015-5291

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2015-11-02 · updated 2026-06-17
• Weakness: CWE-119

Description

Heap-based buffer overflow in PolarSSL 1.x before 1.2.17 and ARM mbed TLS (formerly PolarSSL) 1.3.x before 1.3.14 and 2.x before 2.1.2 allows remote SSL servers to cause a denial of service (client crash) and possibly execute arbitrary code via a long hostname to the server name indication (SNI) extension, which is not properly handled when creating a ClientHello message. NOTE: this identifier has been SPLIT per ADT3 due to different affected version ranges. See CVE-2015-8036 for the session ticket issue that was introduced in 1.3.0.

Affected products

• Debian Linux: 7.0, 8.0
• Fedoraproject Fedora: 21, 22, 23
• openSUSE Leap: 42.1
• Opensuse: 13.2
• PolarSSL: from 1.0.0 before 1.2.17 — fixed in 1.2.17
• TrustedFirmware Mbed TLS: from 1.3.0 before 1.3.14; from 2.0.0 before 2.1.2 — fixed in 1.3.14, 2.1.2

How to fix

Upgrade to a fixed version: PolarSSL 1.2.17; TrustedFirmware Mbed TLS 1.3.14, 2.1.2. Check the vendor advisory for mitigations.

References

• http://lists.fedoraproject.org/pipermail/package-announce/2015-November/170317.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169625.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169765.html
• http://lists.opensuse.org/opensuse-security-announce/2015-12/msg00013.html
• http://lists.opensuse.org/opensuse-updates/2015-12/msg00119.html
• http://www.debian.org/security/2016/dsa-3468
• https://guidovranken.files.wordpress.com/2015/10/cve-2015-5291.pdf
• https://guidovranken.wordpress.com/2015/10/07/cve-2015-5291/
• https://security.gentoo.org/glsa/201706-18
• https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2015-01
• http://lists.fedoraproject.org/pipermail/package-announce/2015-November/170317.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-October/169625.html

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