Vulnerability Name:

CVE-2021-20317 (CCN-210135)

Assigned:2020-12-17
Published:2021-09-23
Updated:2022-06-14
Summary:A flaw was found in the Linux kernel. A corrupted timer tree caused the task wakeup to be missing in the timerqueue_add function in lib/timerqueue.c. This flaw allows a local attacker with special user privileges to cause a denial of service, slowing and eventually stopping the system while running OSP.
CVSS v3 Severity:4.4 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)
3.9 Low (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
5.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
4.8 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:U/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): None
Integrity (I): None
Availibility (A): High
4.4 Medium (REDHAT CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)
3.9 Low (REDHAT Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:4.9 Medium (CVSS v2 Vector: AV:L/AC:L/Au:N/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
4.6 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-665
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-20317

Source: CCN
Type: Red Hat Bugzilla - Bug 2005258
(CVE-2021-20317) - CVE-2021-20317 kernel: timer tree corruption leads to missing wakeup and system freez

Source: MISC
Type: Issue Tracking, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2005258

Source: CONFIRM
Type: UNKNOWN
https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf

Source: XF
Type: UNKNOWN
linux-kernel-cve202120317-dos(210135)

Source: CCN
Type: Linux Kernel GIT Repository
lib/timerqueue: Rely on rbtree semantics for next timer

Source: MISC
Type: Patch, Vendor Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=511885d7061eda3eb1faf3f57dcc936ff75863f1

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20211216 [SECURITY] [DLA 2843-1] linux security update

Source: MLIST
Type: Mailing List, Third Party Advisory
[debian-lts-announce] 20220309 [SECURITY] [DLA 2941-1] linux-4.19 security update

Source: DEBIAN
Type: Third Party Advisory
DSA-5096

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2021-20317

Vulnerable Configuration:Configuration 1:
  • cpe:/o:linux:linux_kernel:*:*:*:*:*:*:*:* (Version < 5.4)
  • OR cpe:/o:linux:linux_kernel:5.4:-:*:*:*:*:*:*

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

    • Configuration RedHat 1:
  • cpe:/a:redhat:enterprise_linux:8:*:*:*:*:*:*:*

    • Configuration RedHat 2:
  • cpe:/a:redhat:enterprise_linux:8::nfv:*:*:*:*:*

    • Configuration RedHat 3:
  • cpe:/a:redhat:enterprise_linux:8::realtime:*:*:*:*:*

    • Configuration RedHat 4:
  • cpe:/a:redhat:enterprise_linux:8::crb:*:*:*:*:*

    • Configuration RedHat 5:
  • cpe:/o:redhat:enterprise_linux:8:*:*:*:*:*:*:*

    • Configuration RedHat 6:
  • cpe:/o:redhat:enterprise_linux:8::baseos:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/o:linux:linux_kernel:5.3:-:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.redhat.rhsa:def:20214646
    P
    		RHSA-2021:4646: kernel-rt security and bug fix update (Important)
    2021-11-15
    oval:com.redhat.rhsa:def:20214647
    P
    		RHSA-2021:4647: kernel security update (Important)
    2021-11-15
    BACK
    linux linux kernel *
    linux linux kernel 5.4 -
    debian debian linux 9.0
    debian debian linux 10.0
    linux linux kernel 5.3