CVE-2020-13777
gnutls: session resumption works without master key allowing MITM
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.
GnuTLS versiones 3.6.x anteriores a 3.6.14, usa una criptografía incorrecta para cifrar un ticket de sesión (una pérdida de confidencialidad en TLS versión 1.2, y un desvío de autenticación en TLS versión 1.3). La primera versión afectada es la 3.6.4 (24-09-2018) debido a un error en un commit del 18-09-2018. Hasta la primera rotación de claves, el servidor TLS siempre utiliza datos erróneos en lugar de una clave de cifrado derivada de una aplicación
A flaw was found in GnuTLS, in versions starting from 3.6.4, where it does not session the ticket encryption key in a secure fashion by the application which is connecting. This flaw allows an attacker to craft a man-in-the-middle-attack, with the ability to bypass the TLS1.3 authentication and also recover older conversations when TLS1.2 is in use. The highest threat to this flaw is to confidentiality and integrity.
CVSS Scores
SSVC
- Decision:-
Timeline
- 2020-06-03 CVE Reserved
- 2020-06-04 CVE Published
- 2024-08-04 CVE Updated
- 2024-09-28 EPSS Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
- CWE-327: Use of a Broken or Risky Cryptographic Algorithm
- CWE-345: Insufficient Verification of Data Authenticity
CAPEC
References (12)
| URL | Tag | Source |
|---|---|---|
| https://security.netapp.com/advisory/ntap-20200619-0004 | Third Party Advisory |
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Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Gnu Search vendor "Gnu" | Gnutls Search vendor "Gnu" for product "Gnutls" | >= 3.6.0 < 3.6.14 Search vendor "Gnu" for product "Gnutls" and version " >= 3.6.0 < 3.6.14" | - |
Affected
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| Fedoraproject Search vendor "Fedoraproject" | Fedora Search vendor "Fedoraproject" for product "Fedora" | 31 Search vendor "Fedoraproject" for product "Fedora" and version "31" | - |
Affected
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| Fedoraproject Search vendor "Fedoraproject" | Fedora Search vendor "Fedoraproject" for product "Fedora" | 32 Search vendor "Fedoraproject" for product "Fedora" and version "32" | - |
Affected
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| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 19.10 Search vendor "Canonical" for product "Ubuntu Linux" and version "19.10" | - |
Affected
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| Canonical Search vendor "Canonical" | Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux" | 20.04 Search vendor "Canonical" for product "Ubuntu Linux" and version "20.04" | lts |
Affected
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| Debian Search vendor "Debian" | Debian Linux Search vendor "Debian" for product "Debian Linux" | 10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0" | - |
Affected
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