NVD Vulnerability Detail

CVE-2020-25212

Summary	A TOCTOU mismatch in the NFS client code in the Linux kernel before 5.8.3 could be used by local attackers to corrupt memory or possibly have unspecified other impact because a size check is in fs/nfs/nfs4proc.c instead of fs/nfs/nfs4xdr.c, aka CID-b4487b935452.
Publication Date	Sept. 10, 2020, 1:15 a.m.
Registration Date	Jan. 26, 2021, 11:55 a.m.
Last Update	Nov. 21, 2024, 2:17 p.m.

CVSS3.1 : HIGH
スコア	7.0
Vector	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
攻撃元区分(AV)	ローカル
攻撃条件の複雑さ(AC)	高
攻撃に必要な特権レベル(PR)	低
利用者の関与(UI)	不要
影響の想定範囲(S)	変更なし
機密性への影響(C)	高
完全性への影響(I)	高
可用性への影響(A)	高

CVSS2.0 : MEDIUM
Score	4.4
Vector	AV:L/AC:M/Au:N/C:P/I:P/A:P
攻撃元区分(AV)	ローカル
攻撃条件の複雑さ(AC)	中
攻撃前の認証要否(Au)	不要
機密性への影響(C)	低
完全性への影響(I)	低
可用性への影響(A)	低
Get all privileges.	いいえ
Get user privileges	いいえ
Get other privileges	いいえ
User operation required	いいえ

Affected software configurations

Configuration1		or higher	or less	more than	less than
cpe:2.3:o:linux:linux_kernel::::::::					5.8.3

Configuration2		or higher	or less	more than	less than
cpe:2.3:o:debian:debian_linux:9.0:::::::*

Configuration3	or higher	or less	more than	less than
cpe:2.3:o:opensuse:leap:15.1:::::::*
cpe:2.3:o:opensuse:leap:15.2:::::::*

Configuration4	or higher	or less	more than	less than
cpe:2.3:o:canonical:ubuntu_linux:18.04::::lts:::
cpe:2.3:o:canonical:ubuntu_linux:14.04::::esm:::
cpe:2.3:o:canonical:ubuntu_linux:20.04::::lts:::
cpe:2.3:o:canonical:ubuntu_linux:16.04::::esm:::

Related information, measures and tools

No	URL	タグ
1	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html	Mailing List Third Party Advisory
2	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html	Mailing List Third Party Advisory
3	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00035.html	Mailing List Third Party Advisory
4	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00035.html	Mailing List Third Party Advisory
5	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html	Mailing List Third Party Advisory
6	http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html	Mailing List Third Party Advisory
7	https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.3	Mailing List Vendor Advisory
8	https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.3	Mailing List Vendor Advisory
9	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4487b93545214a9db8cbf32e86411677b0cca21	Mailing List Patch Vendor Advisory
10	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4487b93545214a9db8cbf32e86411677b0cca21	Mailing List Patch Vendor Advisory
11	https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html	Mailing List Third Party Advisory
12	https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html	Mailing List Third Party Advisory
13	https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html	Mailing List Third Party Advisory
14	https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html	Mailing List Third Party Advisory
15	https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html	Mailing List Third Party Advisory
16	https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html	Mailing List Third Party Advisory
17	https://twitter.com/grsecurity/status/1303370421958578179	Third Party Advisory
18	https://twitter.com/grsecurity/status/1303370421958578179	Third Party Advisory
19	https://usn.ubuntu.com/4525-1/	Third Party Advisory
20	https://usn.ubuntu.com/4525-1/	Third Party Advisory
21	https://usn.ubuntu.com/4527-1/	Third Party Advisory
22	https://usn.ubuntu.com/4527-1/	Third Party Advisory
23	https://usn.ubuntu.com/4578-1/	Third Party Advisory
24	https://usn.ubuntu.com/4578-1/	Third Party Advisory

Common Vulnerabilities List

No	CWE	Name	URL
1	CWE-787	境界外書き込み	https://cwe.mitre.org/data/definitions/787.html
2	CWE-367	Time-of-check Time-of-use (TOCTOU) 競合状態	https://cwe.mitre.org/data/definitions/367.html

JVN Vulnerability Information

Linux kernel におけるTime-of-check Time-of-use (TOCTOU) 競合状態の脆弱性

Title	Linux kernel におけるTime-of-check Time-of-use (TOCTOU) 競合状態の脆弱性
Summary	Linux kernel には、Time-of-check Time-of-use (TOCTOU) 競合状態の脆弱性が存在します。ベンダは、本脆弱性を CID-b4487b935452 として公開しています。
Possible impacts	情報を取得される、情報を改ざんされる、およびサービス運用妨害 (DoS) 状態にされる可能性があります。
Solution	ベンダより正式な対策が公開されています。ベンダ情報を参照して適切な対策を実施してください。
Publication Date	Aug. 21, 2020, midnight
Registration Date	Feb. 12, 2021, 3:41 p.m.
Last Update	Feb. 12, 2021, 3:41 p.m.

Affected System

Linux

Linux Kernel 5.8.3 未満

CVE (情報セキュリティ共通脆弱性識別子)

No	Name	URL
Common Vulnerabilities and Exposures (CVE)
1	CVE-2020-25212	https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25212
National Vulnerability Database (NVD)
2	CVE-2020-25212	https://nvd.nist.gov/vuln/detail/CVE-2020-25212

CWE (共通脆弱性タイプ一覧)

No	Name	URL
JVNDB
1	CWE-367	https://cwe.mitre.org/data/definitions/367.html

ベンダー情報

No	Name	URL
ChangeLog
1	ChangeLog-5.8.3	https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.3
Linux Kernel
2	Linux Kernel Archives	http://www.kernel.org
Linux kernel source tree
3	nfs: Fix getxattr kernel panic and memory overflow	https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b4487b93545214a9db8cbf32e86411677b0cca21

Change Log

No	Changed Details	Date of change
1	[2021年02月12日] 掲載	Feb. 12, 2021, 3:41 p.m.