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NVD / CVE Program· CNA fortinet

CVE-2018-13383: A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and…

MediumCVSS 6.5 · v3.1KEVWeaponized No fix recorded

Noroxi assessment

Priority: This week (action score 65/100)

  • CISA has confirmed exploitation in the wild (Jan 10, 2022); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Jul 10, 2022.
  • Probability of exploitation in the next 30 days: 30.6% (FIRST EPSS); higher than 98.2% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.
  • Severity is disputed: the assigning authority (CNA) scores it 4.3, NVD 6.5.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Don’t wait for the next maintenance window. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

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 · CISA KEV · FIRST EPSS

A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and FortiProxy 2.0.0, 1.2.8 and earlier in the SSL VPN web portal may cause the SSL VPN web service termination for logged in users due to a failure to properly handle javascript href data when proxying webpages.

Published
May 29, 2019
Updated
Jun 16, 2026
EPSS
30.6% · 98th percentile

Report tools

JSON

Action score

65

This week

Don’t wait for the next maintenance window.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
30 / 30 · Listed
EPSS
9 / 30 · 30.6%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.5
CNA · fortinet
4.3
2.2 point gap

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

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

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jan 10, 2022. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jul 10, 2022.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2018-13383

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

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Affected 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.

VendorProduct
fortinetfortiproxy
fortinetfortios

Versions reported by the vendor

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

  • Fortinet Fortinet FortiOS and FortiProxy

    • FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier, FortiProxy 2.0.0, 1.2.8 and earlieraffected
Affected versions · NVD (4)

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

  • fortinet fortios5.2.0 and later · before 5.2.15
  • fortinet fortios5.4.0 and later · before 5.4.13
  • fortinet fortios5.6.0 and later · before 5.6.11
  • fortinet fortios6.0.0 and later · before 6.0.5

Same product

fortinet: all records

Other highest-scoring records for the same primary product.

  • CVE-2022-40684An authentication bypass using an alternate path or channel [CWE-288] in Fortinet FortiOS version 7.2.0 through 7.2.1 and 7.0.0 through 7.0.KEV
    99Now
  • CVE-2018-13379An Improper Limitation of a Pathname to a Restricted Directory ("Path Traversal") in Fortinet FortiOS 6.0.0 to 6.0.4, 5.6.3 to 5.6.7 and…KEV
    99Now
  • CVE-2024-55591An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS version 7.0.0 through 7.0.16 and…KEV
    97Now

Published before and after this one in the same product

  • Later →CVE-2018-13381Jun 4, 2019 · A buffer overflow vulnerability in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.7, 5.4 and earlier versions and FortiProxy…
    31Monitor
  • Later →CVE-2018-13382Jun 4, 2019 · An Improper Authorization vulnerability in Fortinet FortiOS 6.0.0 to 6.0.4, 5.6.0 to 5.6.8 and 5.4.1 to 5.4.10 and FortiProxy 2.0.0, 1.2.0…KEV
    85Now
  • Later →CVE-2020-6648Oct 21, 2020 · A cleartext storage of sensitive information vulnerability in FortiOS command line interface in versions 6.2.4 and earlier and FortiProxy 2.
    26Monitor

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

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. CISA KEV+956 d
  3. TodayNov 14, 2026+2726 d
EPSS, last 120 days-2% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records