HOMEVULNERABILITIESCVE-2021-23240
HIGH

CVE-2021-23240

CWE-59Published: January 12, 2021· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official Description

selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.

NVD Source

Technical Analysis

CVE-2021-23240 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Fedora1 product(s)
fedora
netapp2 product(s)
hci management nodesolidfire
sudo_project1 product(s)
sudo
Source: NVD CPE · 5 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23240
PATCHhttps://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23240
ADVISORYhttps://security.gentoo.org/glsa/202101-33
ADVISORYhttps://security.netapp.com/advisory/ntap-20210129-0010/
ADVISORYhttps://www.sudo.ws/stable.html#1.9.5
ADVISORYhttps://security.gentoo.org/glsa/202101-33
ADVISORYhttps://security.netapp.com/advisory/ntap-20210129-0010/
ADVISORYhttps://www.sudo.ws/stable.html#1.9.5

All References (16)

→
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23240Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
→
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EE42Y35SMJOLONAIBNYNFC7J44UUZ2Y6/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GMY4VSSBIND7VAYSN6T7XIWJRWG4GBB3/
→
https://security.gentoo.org/glsa/202101-33Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20210129-0010/Third Party Advisory
→
https://www.sudo.ws/stable.html#1.9.5Release Notes · Vendor Advisory
→
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23240Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
→
https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EE42Y35SMJOLONAIBNYNFC7J44UUZ2Y6/
→
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GMY4VSSBIND7VAYSN6T7XIWJRWG4GBB3/
→
https://security.gentoo.org/glsa/202101-33Third Party Advisory
→
https://security.netapp.com/advisory/ntap-20210129-0010/Third Party Advisory

Quick Facts

CVE IDCVE-2021-23240
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-59
CISA KEVNo
Affected3 vendor(s)
PublishedJan 12, 2021

Related CVEs (CWE-59)

CVE-2002-2374
10.0
CVE-2024-28189
10.0
CVE-2014-4480
10.0
CVE-2024-28185
10.0
CVE-2026-7374
9.9
CVE-2018-5225
9.9

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-23240 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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