Vulnerability Name:

CVE-2021-3178 (CCN-241803)

Assigned:2021-01-19
Published:2021-01-19
Updated:2021-03-25
Summary:** DISPUTED ** fs/nfsd/nfs3xdr.c in the Linux kernel through 5.10.8, when there is an NFS export of a subdirectory of a filesystem, allows remote attackers to traverse to other parts of the filesystem via READDIRPLUS.
Note: some parties argue that such a subdirectory export is not intended to prevent this attack; see also the exports(5) no_subtree_check default behavior.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): None
6.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N)
5.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): High
Integrity (I): High
Availibility (A): None
CVSS v2 Severity:5.5 Medium (CVSS v2 Vector: AV:N/AC:L/Au:S/C:P/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): None
8.5 High (CCN CVSS v2 Vector: AV:N/AC:L/Au:S/C:C/I:C/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): Complete
Integrity (I): Complete
Availibility (A): None
Vulnerability Type:CWE-22
Vulnerability Consequences:Obtain Information
References:Source: MITRE
Type: CNA
CVE-2021-3178

Source: XF
Type: UNKNOWN
linux-kernel-cve20213178-dir-traversal(241803)

Source: CCN
Type: Linux Kernel GIT Repository
nfsd4: readdirplus shouldn't return parent of export

Source: CCN
Type: Mend Vulnerability Database
CVE-2021-3178

Vulnerable Configuration:Configuration CCN 1:
  • cpe:/o:linux:linux_kernel:5.10.8:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    linux linux kernel 5.10.8