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CVE Record

CVE-2025-27621: UpTrain has a Constant Default API Key

UpTrain is an open-source platform to evaluate and improve generative AI applications. In version 0.7.1 and prior, the UpTrain backend creates a new default user with a static username, where the username is also used as the default API key. The UpTrain backend also has an open CORS policy. Using these two primitives, any website can make a authenticated cross-origin request to the UpTrain instance by providing the default API key in the header `uptrain-access-token`. This issue may allow arbitrary websites to perform privileged operations on the UpTrain instance, as if they were the default logged in user. As of time of publication, no known patches are available.

HighCVSS 7.7Not KEV-listedUpdated
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Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

UpTrain 0.7.1 and earlier create a default user whose static username also serves as its API key. Combined with permissive cross-origin access, an arbitrary website may act as that user and perform privileged operations. This threatens the integrity of exposed UpTrain environments.

Executive priority

Treat reachable affected backends as a high-priority integrity risk. Immediately reduce exposure, verify whether default credentials remain active, and monitor for misuse. Because no patch is identified, require tracked vendor follow-up and documented compensating controls rather than assuming an upgrade exists.

Technical view

The backend uses a predictable default credential accepted through the uptrain-access-token header and permits open CORS. A remote attacker can therefore submit authenticated cross-origin requests without prior privileges or user interaction. The supplied CVSS 4.0 score is 7.7, with high integrity impact and no stated confidentiality or availability impact.

Likely exposure

Exposure is most likely where UpTrain 0.7.1 or earlier runs the dashboard backend, retains the default user credential, and is reachable from users' browsers or untrusted networks. The source bundle does not identify hosted services, deployment defaults, or internet-wide prevalence.

Exploitation context

The supplied CVSS vector marks proof-of-concept maturity, but the source bundle provides no evidence of active exploitation. The CVE is not listed as KEV. Exploitation requires network reachability but reportedly needs no privileges, special conditions, or user interaction.

Researcher notes

The issue is an authentication weakness, CWE-287, created by a static default identity and credential, amplified by open CORS. The cited source snapshot shows the relevant backend implementation. Evidence is insufficient to establish confidentiality impact, availability impact, affected deployment prevalence, active exploitation, or a vendor-approved remediation.

Mitigation direction

  • Identify and restrict network access to UpTrain backend instances running version 0.7.1 or earlier.
  • Remove or replace the default credential only through vendor-supported configuration.
  • Limit permitted CORS origins as a compensating control where safely supported.
  • Check current UpTrain vendor guidance regularly; the sources name no available patch.
  • Monitor backend activity for unexpected privileged operations or use of the default identity.

Validation and detection

  • Inventory deployed UpTrain versions and flag every backend running version 0.7.1 or earlier.
  • Determine whether the documented default user and API key remain enabled.
  • Review CORS configuration for unrestricted origins on each affected backend.
  • Confirm affected services are not reachable from untrusted networks or browser contexts.
  • Review logs for unexpected requests authenticated as the default user.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-287: Credential and account abuse lookup

Authentication and credential weaknesses can make valid-account abuse and credential telemetry useful review starting points. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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description · low confidence lookup

Credential and access behavior lookup

The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-27621 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.7 (4.0)
Known Exploited
No
Published

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
1ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: yesTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.7CVSS 4.0HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P——GitHub_M

Vulnerability scoring details

Base CVSS 4.0 score

7.7High
CVSS 4.0 vector shape for CVE-2025-27621Attack VectorAttack ComplexityAttack RequirementsPrivileges RequiredUser InteractionVS ConfidentialityVS IntegrityVS AvailabilitySS ConfidentialitySS IntegritySS Availability

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Attack Requirements
NonePresent
Privileges Required
NoneLowHigh
User Interaction
NonePassiveActive
VS Confidentiality
HighLowNone
VS Integrity
HighLowNone
VS Availability
HighLowNone
SS Confidentiality
HighLowNone
SS Integrity
HighLowNone
SS Availability
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
uptrain-aiuptrain<= 0.7.1Listed
Weakness

CWE details

CWE-287

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-287 · source CWE mapping

Improper Authentication

Improper Authentication represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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