CVE-2021-23239: The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning
Noroxi assessment
Priority: Monitor (action score 10/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 1% (FIRST EPSS); higher than 63.8% of all records.
- Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: sudo (Alpine:v3.10) 1.9.5p2-r0; sudo (Alpine:v3.12) 1.9.5-r0; sudo (Debian:10) 1.8.27-1+deb10u4.
- Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to sudo (Alpine:v3.10) 1.9.5p2-r0; sudo (Alpine:v3.12) 1.9.5-r0; sudo (Debian:10) 1.8.27-1+deb10u4 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory by a symlink to an arbitrary path.
- Published
- Jan 12, 2021
- Updated
- Jun 16, 2026
- EPSS
- 1.0% · 63th percentile
- CWE
- CWE-59
Report tools
Action score
10
Monitor
Low priority for now.
- CVSS
- 10 / 40 · 2.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.0%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| sudo project | sudo | cpe:2.3:a:sudo_project:sudo |
| netapp | cloud backup | cpe:2.3:a:netapp:cloud_backup |
| netapp | hci management node | cpe:2.3:a:netapp:hci_management_node |
| netapp | solidfire | cpe:2.3:a:netapp:solidfire |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux10.0
- fedoraproject fedora32
- fedoraproject fedora33
- netapp cloud backupall versions
- netapp hci management nodeall versions
- netapp solidfireall versions
- sudo project sudobefore 1.8.32
- sudo project sudo1.9.0 and later · before 1.9.5
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | sudo | from 1.9.0 · before 1.9.5p2-r0 | 1.9.5p2-r0 |
| Alpine:v3.12 | sudo | from 1.9.0 · before 1.9.5-r0 | 1.9.5-r0 |
| Debian:10 | sudo | before 1.8.27-1+deb10u4 | 1.8.27-1+deb10u4 |
| Debian:12 | sudo | before 1.9.5-1 | 1.9.5-1 |
| openSUSE:Leap 15.1 | sudo | before 1.8.22-lp151.5.12.1 | 1.8.22-lp151.5.12.1 |
| openSUSE:Leap 15.2 | sudo | before 1.8.22-lp152.8.6.1 | 1.8.22-lp152.8.6.1 |
| openSUSE:Tumbleweed | sudo | before 1.9.7p2-1.4 | 1.9.7p2-1.4 |
| Red Hat:enterprise_linux:8::baseos | sudo | before 0:1.8.29-7.el8 | 0:1.8.29-7.el8 |
| Red Hat:enterprise_linux:8::baseos | sudo-debuginfo | before 0:1.8.29-7.el8 | 0:1.8.29-7.el8 |
| Red Hat:enterprise_linux:8::baseos | sudo-debugsource | before 0:1.8.29-7.el8 | 0:1.8.29-7.el8 |
| Rocky Linux:8 | sudo | before 0:1.8.29-7.el8 | 0:1.8.29-7.el8 |
| SUSE:HPE Helion OpenStack 8 | sudo | before 1.8.20p2-3.20.1 | 1.8.20p2-3.20.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP1 | sudo | before 1.8.22-4.15.1 | 1.8.22-4.15.1 |
| SUSE:Linux Enterprise Software Development Kit 12 SP5 | sudo | before 1.8.27-4.6.1 | 1.8.27-4.6.1 |
| SUSE:OpenStack Cloud 7 | sudo | before 1.8.10p3-10.29.1 | 1.8.10p3-10.29.1 |
Same product
sudo project: all recordsOther highest-scoring records for the same primary product.
- CVE-2021-3156Sudo before 1.9.5p2 contains an off-by-one error that can result in a heap-based buffer overflow, which allows privilege escalation to root KEV91Now
- CVE-2025-32463Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf from a user-controlled directory is used with the -KEV78This week
- CVE-2019-14287In Sudo before 1.8.28, an attacker with access to a Runas ALL sudoer account can bypass certain policy blacklists and session PAM modules, a54Plan
Published before and after this one in the same product
- ← EarlierCVE-2019-18684Nov 4, 2019 · Sudo through 1.8.29 allows local users to escalate to root if they have write access to file descriptor 3 of the sudo process.28Monitor
- ← EarlierCVE-2019-18634Jan 29, 2020 · In Sudo before 1.8.26, if pwfeedback is enabled in /etc/sudoers, users can trigger a stack-based buffer overflow in the privileged sudo proc37Monitor
- Later →CVE-2021-23240Jan 12, 2021 · selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:sudo | 1.9.5p2-r0 · Alpine:v3.10 | Package registry (OSV) |
| debian:sudo | 1.9.5-1 · Debian:12 | Package registry (OSV) |
| opensuse:sudo | 1.8.22-lp151.5.12.1 · openSUSE:Leap 15.1 | Package registry (OSV) |
| red hat:sudo | 0:1.8.29-7.el8 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:sudo-debuginfo | 0:1.8.29-7.el8 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| red hat:sudo-debugsource | 0:1.8.29-7.el8 · Red Hat:enterprise_linux:8::baseos | Package registry (OSV) |
| rocky linux:sudo | 0:1.8.29-7.el8 · Rocky Linux:8 | Package registry (OSV) |
| suse:sudo | 1.8.27-4.6.1 · SUSE:Linux Enterprise Software Development Kit 12 SP5 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-21-0084 · Jan 29, 2021(Sudo Güvenlik Zafiyeti)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- low · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Local
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- Low
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-59 · Improper Link Resolution Before File Access ('Link Following')CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
- Obfuscated Files or Information: HTML SmugglingT1027.006
- Obfuscated Files or Information: Embedded PayloadsT1027.009
- Boot or Logon Autostart Execution:Shortcut ModificationT1547.009
- Hide Artifacts: Resource ForkingT1564.009
- Hijack Execution Flow: Executable Installer File Permissions WeaknessT1574.005
- Hijack Execution Flow: Services File Permissions WeaknessT1574.010
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (5 more)Show less
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EE42Y35SMJOLONAIBNYNFC7J44UUZ2Y6/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GMY4VSSBIND7VAYSN6T7XIWJRWG4GBB3/
- security.gentoo.org/glsa/202101-33
- security.netapp.com/advisory/ntap-20210129-0010/
- www.sudo.ws/stable.html#1.9.5
Vendor advisories and official records. Exploit/PoC links are deliberately left out.