CVE-2023-34388

Unauthenticated session hijacking and authentication bypass

Published Nov 30, 2023 · Updated Jun 3, 2025

Improper authentication in SEL-451 firmware allows remote attackers on an adjacent network to hijack sessions and bypass login. SEL has not published the affected authentication locus or the incorrect operation that accepts an unauthorized session. No credentials or user interaction are required, and exploitation grants the hijacked session's authority without reported confidentiality or availability impact.

CVSS severity9.8
Critical
EPSS probability0.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper authentication in SEL-451 firmware allows remote attackers on an adjacent network to hijack sessions and bypass login. SEL has not published the affected authentication locus or the incorrect operation that accepts an unauthorized session. No credentials or user interaction are required, and exploitation grants the hijacked session's authority without reported confidentiality or availability impact.

The record

CVE
CVE-2023-34388
Published
Nov 30, 2023
Updated
Jun 3, 2025
Vendor
Schweitzer Engineering Laboratories
Product
SEL-451 Protection, Automation, and Bay Control System
Classifications
CWE-287, T1550
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 30, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=R315-V0 <R315-V4
  2. Affected versionversion=R316-V0 <R316-V4
  3. Affected versionversion=R317-V0 <R317-V4
  4. Affected versionversion=R318-V0 <R318-V5
  5. Affected versionversion=R320-V0 <R320-V3
  6. Affected versionversion=R321-V0 <R321-V3
  7. Affected versionversion=R322-V0 <R322-V3
  8. Affected versionversion=R323-V0 <R323-V5
  9. Affected versionversion=R324-V0 <R324-V4
  10. Affected versionversion=R325-V0 <R325-V3
  11. Affected versionversion=R326-V0 <R326-V1
  12. Affected versionversion=R327-V0 <R327-V1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Schweitzer Engineering Laboratories · SEL-451 Protection, Automation, and Bay Control Systemversion=R315-V0 <R315-V4; version=R316-V0 <R316-V4; version=R317-V0 <R317-V4; version=R318-V0 <R318-V5; version=R320-V0 <R320-V3; version=R321-V0 <R321-V3; version=R322-V0 <R322-V3; version=R323-V0 <R323-V5; version=R324-V0 <R324-V4; version=R325-V0 <R325-V3; version=R326-V0 <R326-V1; version=R327-V0 <R327-V1

Published CVSS scores

6.5Schweitzer Engineering LaboratoriesCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-287Improper Authentication
T1550Use Alternate Authentication Material

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo