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CVE-2018-15686· NVD / CVE Program· CNA canonical

systemd: reexec state injection: fgets() on overlong lines leads to line splitting

A vulnerability in unit_deserialize of systemd allows an attacker to supply arbitrary state across systemd re-execution via NotifyAccess. This can be used to improperly influence systemd execution and possibly lead to root privilege escalation. Affected releases are systemd versions up to and including 239.

HighCVSS 7.8 · v3.1—Proof of concept Fix available
Published
Oct 26, 2018
Updated
Jun 16, 2026
EPSS
2.3% · 82th percentile
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JSON

Action score

32

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 2.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.8
CNA · canonical
7.0
0.8 point gap

CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
canonicalubuntu linux
debiandebian linux
systemd projectsystemd
oraclecommunications cloud native core network function cloud native environment

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • canonical ubuntu linux16.04
  • canonical ubuntu linux18.04
  • canonical ubuntu linux18.10
  • debian debian linux8.0
  • oracle communications cloud native core network function cloud native environment1.4.0
  • systemd project systemdup to 239 inclusive

Versions reported by the vendor

Affected version ranges reported by the assigning authority (canonical). Independent of NVD's CPE analysis and usually ahead of it.

  • systemd systemd

    • unspecified and later · up to and including 239affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12systemdbefore 239-12239-12
Debian:8systemdbefore 215-17+deb8u8215-17+deb8u8
openSUSE:Tumbleweedsystemdbefore 249.4-2.2249.4-2.2
Red Hat:enterprise_linux:7::clientlibgudev1before 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientlibgudev1-develbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemdbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-debuginfobefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-develbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-journal-gatewaybefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-libsbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-networkdbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-pythonbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-resolvedbefore 0:219-67.el70:219-67.el7
Red Hat:enterprise_linux:7::clientsystemd-sysvbefore 0:219-67.el70:219-67.el7
Red Hat:rhel_aus:7.4::serverlibgudev1before 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serverlibgudev1-develbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemdbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-debuginfobefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-develbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-journal-gatewaybefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-libsbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-networkdbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-pythonbefore 0:219-42.el7_4.200:219-42.el7_4.20
Red Hat:rhel_aus:7.4::serversystemd-resolvedbefore 0:219-42.el7_4.200:219-42.el7_4.20

+27

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Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:systemd239-12 · Debian:12Package registry (OSV)
opensuse:systemd249.4-2.2 · openSUSE:TumbleweedPackage registry (OSV)
red hat:libgudev10:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:libgudev1-devel0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-debuginfo0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-devel0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-journal-gateway0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-libs0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-networkd0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-python0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-resolved0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
red hat:systemd-sysv0:219-67.el7 · Red Hat:enterprise_linux:7::clientPackage registry (OSV)
suse:systemd234-24.15.1 · SUSE:Linux Enterprise Module for Basesystem 15Package 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
  • Proof-of-concept repository on GitHub ×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.

Public exploit evidence
SourceKindDate
Exploit-DB entrydos2018-10-29
Proof-of-concept repository on GitHubstars:02019-10-03

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.

  1. Published
  2. First PoC+3 d
  3. TodaySep 30, 2026+2896 d
EPSS, last 120 days

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.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

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

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

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.

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Change log

  1. Fix✗ → ✓

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References

All records