Vulnerability Name:

CVE-2016-9243 (CCN-124358)

Assigned:2016-11-24
Published:2016-11-24
Updated:2017-04-04
Summary:HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.
CVSS v3 Severity:7.5 High (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N)
6.5 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): None
4.8 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N)
4.2 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): Low
Availibility (A): None
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
4.0 Medium (CCN CVSS v2 Vector: AV:N/AC:H/Au:N/C:P/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): High
Athentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): None
Vulnerability Type:CWE-20
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2016-9243

Source: MLIST
Type: Mailing List, Patch, VDB Entry
[oss-security] 20161109 Re: CVE Request: Cryptography 1.5.3: HKDF might return an empty byte-string

Source: BID
Type: Third Party Advisory, VDB Entry
94216

Source: CCN
Type: BID-94216
Python Cryptography CVE-2016-9243 Security Bypass Vulnerability

Source: UBUNTU
Type: Third Party Advisory
USN-3138-1

Source: CONFIRM
Type: Release Notes, Third Party Advisory
https://cryptography.io/en/latest/changelog

Source: XF
Type: UNKNOWN
python-cryptography-cve20169243-sec-bypass(124358)

Source: CONFIRM
Type: Patch, Third Party Advisory
https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874

Source: CONFIRM
Type: Third Party Advisory
https://github.com/pyca/cryptography/issues/3211

Source: FEDORA
Type: Third Party Advisory
FEDORA-2016-e77c8c1f3b

Source: FEDORA
Type: Third Party Advisory
FEDORA-2016-2d90e27e50

Source: FEDORA
Type: Third Party Advisory
FEDORA-2016-d3a2b640ce

Source: CCN
Type: Python Web site
cryptography

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2016-9243

Vulnerable Configuration:Configuration 1:
  • cpe:/a:cryptography.io:cryptography:*:*:*:*:*:*:*:* (Version <= 1.5.2)

    • Configuration 2:
  • cpe:/o:fedoraproject:fedora:23:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:24:*:*:*:*:*:*:*
  • OR cpe:/o:fedoraproject:fedora:25:*:*:*:*:*:*:*

    • Configuration 3:
  • cpe:/o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
  • OR cpe:/o:canonical:ubuntu_linux:16.10:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.xenial:def:20169243000
    V
    		CVE-2016-9243 on Ubuntu 16.04 LTS (xenial) - medium.
    2017-03-27
    oval:com.ubuntu.xenial:def:201692430000000
    V
    		CVE-2016-9243 on Ubuntu 16.04 LTS (xenial) - medium.
    2017-03-27
    BACK
    cryptography.io cryptography *
    fedoraproject fedora 23
    fedoraproject fedora 24
    fedoraproject fedora 25
    canonical ubuntu linux 16.04
    canonical ubuntu linux 16.10