systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlin
systemd-tmpfiles in systemd before 237 attempts to support ownership/permission changes on hardlinked files even if the fs.protected_hardlinks sysctl is turned off, which allows local users to bypass intended access restrictions via vectors involving a hard link to a file for which the user lacks write access, as demonstrated by changing the ownership of the /etc/passwd file.
- Published
- Jan 29, 2018
- Updated
- Jun 16, 2026
- EPSS
- 1.1% · 63th percentile
- CWE
- CWE-59
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.1%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| systemd project | systemd | cpe:2.3:a:systemd_project:systemd |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
| opensuse | leap | cpe:2.3:o:opensuse:leap |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- debian debian linux8.0
- opensuse leap42.3
- systemd project systemdbefore 237
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | systemd | before 237-1 | 237-1 |
| Debian:8 | systemd | before 215-17+deb8u12 | 215-17+deb8u12 |
| openSUSE:Tumbleweed | systemd | before 249.4-2.2 | 249.4-2.2 |
| SUSE:Linux Enterprise Desktop 12 SP2 | systemd | before 228-150.32.1 | 228-150.32.1 |
Same product
systemd project: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-9445In systemd through 233, certain sizes passed to dns_packet_new in systemd-resolved can cause it to allocate a buffer that's too small.46Plan
- CVE-2018-21029systemd 239 through 245 accepts any certificate signed by a trusted certificate authority for DNS Over TLS.40Plan
- CVE-2015-7510Stack-based buffer overflow in the getpwnam and getgrnam functions of the NSS module nss-mymachines in systemd.40Plan
- CVE-2017-1000082systemd v233 and earlier fails to safely parse usernames starting with a numeric digit (e.g.40Plan
- CVE-2022-2526A use-after-free vulnerability was found in systemd.39Monitor
- CVE-2017-15908In systemd 223 through 235, a remote DNS server can respond with a custom crafted DNS NSEC resource record to trigger an infinite loop in th37Monitor
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 |
|---|---|---|
| debian:systemd | 237-1 · Debian:12 | Package registry (OSV) |
| opensuse:systemd | 249.4-2.2 · openSUSE:Tumbleweed | Package registry (OSV) |
| suse:systemd | 228-150.32.1 · SUSE:Linux Enterprise Desktop 12 SP2 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Exploit-DB entry ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | local | 2018-01-29 |
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.
- First PoCsame day
- Published
- TodaySep 30, 2026+3166 d
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).
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.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-59 · Improper Link Resolution Before File Access ('Link Following')CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.opensuse.org/opensuse-updates/2018-02/msg00109.html
- lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- lists.debian.org/debian-lts-announce/2019/04/msg00022.html
- www.openwall.com/lists/oss-security/2018/01/29/4
Vendor advisories and official records. Exploit/PoC links are deliberately left out.