Vulnerability Name:

CVE-2019-18978 (CCN-171599)

Assigned:2019-11-13
Published:2019-11-13
Updated:2021-05-21
Summary:An issue was discovered in the rack-cors (aka Rack CORS Middleware) gem before 1.0.4 for Ruby. It allows ../ directory traversal to access private resources because resource matching does not ensure that pathnames are in a canonical format.
CVSS v3 Severity:5.3 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)
4.6 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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): Low
Integrity (I): None
Availibility (A): None
7.3 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)
6.4 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/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): Low
Integrity (I): Low
Availibility (A): Low
CVSS v2 Severity:5.0 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:P/I:N/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): None
Availibility (A): None
7.5 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): Partial
Vulnerability Type:CWE-22
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2019-18978

Source: XF
Type: UNKNOWN
rackcors-cve201918978-dir-traversal(171599)

Source: CCN
Type: rack-cors GIT Repository
Unescape and resolve paths before resource checks

Source: MISC
Type: Patch, Third Party Advisory
https://github.com/cyu/rack-cors/commit/e4d4fc362a4315808927011cbe5afcfe5486f17d

Source: MISC
Type: Patch, Third Party Advisory
https://github.com/cyu/rack-cors/compare/v1.0.3...v1.0.4

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20200206 [SECURITY] [DLA 2096-1] ruby-rack-cors security update

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20201001 [SECURITY] [DLA 2389-1] ruby-rack-cors security update

Source: UBUNTU
Type: Third Party Advisory
USN-4571-1

Source: DEBIAN
Type: Third Party Advisory
DSA-4918

Vulnerable Configuration:Configuration 1:
  • cpe:/a:rack-cors_project:rack-cors:*:*:*:*:*:ruby:*:* (Version < 1.0.4)

    • Configuration 2:
  • cpe:/o:debian:debian_linux:8.0:*:*:*:*:*:*:*
  • OR cpe:/o:debian:debian_linux:9.0:*:*:*:*:*:*:*
  • OR cpe:/o:debian:debian_linux:10.0:*:*:*:*:*:*:*

    • Configuration 3:
  • cpe:/o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.disco:def:2019189780000000
    V
    		CVE-2019-18978 on Ubuntu 19.04 (disco) - medium.
    2019-11-14
    oval:com.ubuntu.bionic:def:2019189780000000
    V
    		CVE-2019-18978 on Ubuntu 18.04 LTS (bionic) - medium.
    2019-11-14
    oval:com.ubuntu.xenial:def:2019189780000000
    V
    		CVE-2019-18978 on Ubuntu 16.04 LTS (xenial) - medium.
    2019-11-14
    BACK
    rack-cors_project rack-cors *
    debian debian linux 8.0
    debian debian linux 9.0
    debian debian linux 10.0
    canonical ubuntu linux 16.04