Vulnerability Name:

CVE-2019-15791 (CCN-171524)

Assigned:2019-11-01
Published:2019-11-01
Updated:2020-05-01
Summary:In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, which then puts a reference to that file, leading to a refcount underflow.
CVSS v3 Severity:7.8 High (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
7.0 High (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
8.4 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
7.6 High (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
CVSS v2 Severity:4.6 Medium (CVSS v2 Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): Partial
7.2 High (CCN CVSS v2 Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): Complete
Vulnerability Type:CWE-191
Vulnerability Consequences:Gain Access
References:Source: MITRE
Type: CNA
CVE-2019-15791

Source: CCN
Type: Google Security Research Issue 1957
Ubuntu: refcount underflow and type confusion in shiftfs

Source: XF
Type: UNKNOWN
ubuntu-cve201915791-code-exec(171524)

Source: MISC
Type: Mailing List, Patch, Third Party Advisory
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=601a64857b3d7040ca15c39c929e6b9db3373ec1

Source: CCN
Type: Packet Storm Security [11-14-2019]
Ubuntu shiftfs refcount Underflow / Type Confusion

Source: CCN
Type: Ubuntu Web site
USN-4184-1: Linux kernel vulnerabilities

Source: MISC
Type: Third Party Advisory
https://usn.ubuntu.com/usn/usn-4183-1

Source: MISC
Type: Third Party Advisory
https://usn.ubuntu.com/usn/usn-4184-1

Source: EXPLOIT-DB
Type: EXPLOIT
Offensive Security Exploit Database [11-20-2019]

Source: CCN
Type: IBM Security Bulletin 6205697 (Workload Automation)
Muluple vulnerabilities in Ubuntu affect IBM Workload Scheduler 9.5

Vulnerable Configuration:Configuration 1:
  • cpe:/o:linux:linux_kernel:5.0:-:*:*:*:*:*:*
  • OR cpe:/o:linux:linux_kernel:5.3:-:*:*:*:*:*:*

    • Configuration 2:
  • cpe:/o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
  • OR cpe:/o:canonical:ubuntu_linux:19.04:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/o:canonical:ubuntu:19.04:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.disco:def:2019157910000000
    V
    		CVE-2019-15791 on Ubuntu 19.04 (disco) - medium.
    2019-11-12
    oval:com.ubuntu.bionic:def:2019157910000000
    V
    		CVE-2019-15791 on Ubuntu 18.04 LTS (bionic) - medium.
    2019-11-12
    oval:com.ubuntu.xenial:def:2019157910000000
    V
    		CVE-2019-15791 on Ubuntu 16.04 LTS (xenial) - medium.
    2019-11-12
    BACK
    linux linux kernel 5.0
    linux linux kernel 5.3
    canonical ubuntu linux 18.04
    canonical ubuntu linux 19.04
    canonical ubuntu 19.04