Vulnerability Name:

CVE-2021-20194 (CCN-197421)

Assigned:2020-12-17
Published:2021-01-22
Updated:2023-02-12
Summary:There is a vulnerability in the linux kernel versions higher than 5.2 (if kernel compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to heap overflow (because of non-hardened usercopy). The impact of attack could be deny of service or possibly privileges escalation.
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)
6.8 Medium (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: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): High
Integrity (I): High
Availibility (A): High
7.4 High (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
6.4 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): High
7.0 High (REDHAT CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H)
6.1 Medium (REDHAT Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): High
Privileges Required (PR): Low
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
6.2 Medium (CCN CVSS v2 Vector: AV:L/AC:H/Au:N/C:C/I:C/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): High
Athentication (Au): None
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): Complete
Vulnerability Type:CWE-400
Vulnerability Consequences:Gain Access
References:Source: MITRE
Type: CNA
CVE-2021-20194

Source: CCN
Type: Red Hat Bugzilla – Bug 1912683
(CVE-2021-20194) - CVE-2021-20194 kernel: heap overflow in __cgroup_bpf_run_filter_getsockopt()

Source: secalert@redhat.com
Type: Issue Tracking, Patch, Third Party Advisory
secalert@redhat.com

Source: XF
Type: UNKNOWN
linux-kernel-cve202120194-bo(197421)

Source: CCN
Type: Patchwork Web site
[1/2] bpf: cgroup: Fix optlen WARN_ON_ONCE toctou

Source: secalert@redhat.com
Type: Third Party Advisory
secalert@redhat.com

Source: CCN
Type: WhiteSource Vulnerability Database
CVE-2021-20194

Vulnerable Configuration: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:5.2:-:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.redhat.rhsa:def:20214140
    P
    		RHSA-2021:4140: kernel-rt security and bug fix update (Moderate)
    2021-11-09
    oval:com.redhat.rhsa:def:20214356
    P
    		RHSA-2021:4356: kernel security, bug fix, and enhancement update (Moderate)
    2021-11-09
    BACK
    linux linux kernel 5.2