CVE-2023-25529

Session-token theft via host KVM timing oracle

Published Sep 20, 2023 · Updated Aug 2, 2024

Observable timing discrepancy in the host KVM daemon in NVIDIA DGX H100 and A100 BMC allows remote attackers to steal session tokens. The daemon's token-validation path returns measurably different response times, creating an oracle; NVIDIA has not disclosed the exact comparison operation. Unauthenticated access from an adjacent network is sufficient, and a recovered token enables session impersonation with resulting data access and modification.

CVSS severity8.0
High
EPSS probability0.62%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Observable timing discrepancy in the host KVM daemon in NVIDIA DGX H100 and A100 BMC allows remote attackers to steal session tokens. The daemon's token-validation path returns measurably different response times, creating an oracle; NVIDIA has not disclosed the exact comparison operation. Unauthenticated access from an adjacent network is sufficient, and a recovered token enables session impersonation with resulting data access and modification.

The record

CVE
CVE-2023-25529
Published
Sep 20, 2023
Updated
Aug 2, 2024
Vendor
NVIDIA
Product
NVIDIA DGX A100 BMC
Classifications
CWE-208, CWE-203, T1528
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 20, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=All BMC versions prior to 00.22.05

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

NVIDIA · NVIDIA DGX A100 BMCversion=All BMC versions prior to 00.22.05
NVIDIA · NVIDIA DGX H100 BMCversion=All versions prior to 23.08.07

Published CVSS scores

8.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.0NVIDIA CorporationCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-208Observable Timing Discrepancy
CWE-203Observable Discrepancy
T1528Steal Application Access Token

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

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Your stack

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