dbcve.org
Exynos Modem 5300 FirmwareOperating system · Samsung

CVE-2023-26496

CRITICAL · 9.8 CVSS v3.1 Published 2023-03-23
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in Samsung Baseband Modem Chipset for Exynos Modem 5123, Exynos Modem 5300, Exynos 980, Exynos 1080, and Exynos Auto T5124. Memory corruption can occur due to improper checking of the parameter length while parsing the fmtp attribute in the SDP (Session Description Protocol) module.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Memory corruption vulnerability in Samsung baseband modems (Exynos 5123, 5300, 980, 1080, Auto T5124) due to improper bounds checking when parsing the fmtp attribute in SDP messages, allowing potential buffer overflow and remote code execution in the modem domain.

MitigationApply vendor firmware security updates from Samsung/OEMs to address the baseband modem vulnerability; this is a firmware-level issue requiring patch deployment rather than application-layer mitigation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Exynos Modem 5300 FirmwareOperating system
Affected:all versions
Exynos Modem 5123 FirmwareOperating system
Affected:all versions
Exynos 980 FirmwareOperating system
Affected:all versions
Exynos 1080 FirmwareOperating system
Affected:all versions
Exynos Auto T5123 FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device baseband modem model
    Check the device specifications or use AT commands (e.g., AT+CGMM, AT+CGMR) to query the modem model. For Samsung devices, also check in Settings > About Phone > Modem Firmware or through service codes.
    Affected if The modem model is Exynos 5123, 5300, 980, 1080, or Auto T5123
  2. Confirm Exynos baseband chipset variant
    Cross-reference the modem model with Samsung's chipset documentation or baseband processor identification tools to verify it is an Exynos family baseband processor.
    Affected if The device uses any Samsung Exynos baseband chipset from the affected list
  3. Verify baseband firmware version
    Query the baseband firmware version via AT commands (AT+CGMR) or check in device engineering/bootloader mode. For most consumer devices, this information may be accessible through field test mode (*#*#4636#*#*) or OEM diagnostic tools.
    Affected if Any version of the affected Exynos modem firmware is installed (all versions are vulnerable)
  4. Confirm VoLTE/VoNR service is active
    Check if Voice over LTE or Voice over NR is enabled on the device (Settings > Connections > Mobile Networks > VoLTE). The vulnerability triggers when processing SDP messages during call setup.
    Affected if VoLTE or VoNR is enabled and the device uses an affected Exynos baseband modem (SDP fmtp parsing occurs during VoLTE/VoNR call establishment)

A device is affected if it contains any Samsung Exynos baseband modem (5123, 5300, 980, 1080, or Auto T5123) and has VoLTE/VoNR service enabled, regardless of firmware version since all versions are vulnerable.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware security updates from Samsung/OEMs to address the baseband modem vulnerability; this is a firmware-level issue requiring patch deployment rather than application-layer mitigation.

Recommended fix Moderate confidence
  1. Check Samsung's official security advisory page (security.samsung.com or semiconductor.samsung.com) for available firmware updates for your specific Exynos modem model
  2. Contact Samsung Semiconductor or your device manufacturer to request the patched firmware for Exynos Modem 5300, Exynos Modem 5123, Exynos 980, Exynos 1080, or Exynos Auto T5123
  3. Apply the Samsung-provided firmware update through your device manufacturer or Samsung's official update channels
  4. Verify the SDP fmtp parsing vulnerability is addressed in the applied firmware version
Caveat Firmware updates for baseband modems must be obtained from Samsung or device manufacturers; end-users cannot directly patch modem firmware

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Exynos Modem 5300 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation2.0 h
  • Testing12.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,480
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-26496 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data