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CVE Record

CVE-2021-23338: Deserialization of Untrusted Data

This affects all versions of package qlib. The workflow function in cli part of qlib was using an unsafe YAML load function.

MediumCVSS 6.6Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2021-23338 affects the Python package qlib. Its CLI workflow feature used unsafe YAML loading, so a trusted user with access to run that workflow could cause serious confidentiality, integrity, or availability impact if malicious YAML is processed.

Executive priority

Treat this as a targeted dependency risk, not an internet-wide emergency. Prioritize teams using qlib workflow automation with externally influenced YAML or privileged execution contexts.

Technical view

The issue is deserialization of untrusted data in qlib's CLI workflow function due to an unsafe YAML load function. The CVSS vector indicates network reachability, high attack complexity, high privileges required, no user interaction, unchanged scope, and high C/I/A impact.

Likely exposure

Exposure is most likely in Python environments that install qlib and invoke its CLI workflow processing, especially where YAML workflow input can come from users, partners, CI jobs, or automation.

Exploitation context

The source bundle lists proof-of-concept maturity in CVSS, but KEV is false and no cited source here confirms active exploitation. High privileges and high complexity reduce broad opportunistic risk.

Researcher notes

Evidence is limited to the CVE summary, Snyk reference, and huntr pull request link in the bundle. Do not assume a fixed version, exploit-in-the-wild status, or broader product impact without vendor confirmation.

Mitigation direction

  • Inventory Python environments for qlib and confirm whether the CLI workflow function is used.
  • Do not process untrusted YAML through qlib CLI workflow until vendor guidance is reviewed.
  • Review Snyk and upstream huntr discussion for any fixed release or workaround before upgrading.
  • Restrict access to systems or jobs that can invoke qlib workflow processing.
  • Replace qlib where continued use cannot be justified or safely constrained.

Validation and detection

  • Search dependency manifests and runtime images for qlib.
  • Identify automation paths that feed YAML to qlib workflow.
  • Confirm whether YAML inputs are user-supplied, partner-supplied, or internally generated.
  • Record installed version and compare it with current advisory guidance.
  • Check job history for unexpected qlib workflow invocations.
Prepared
Confidence
medium
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

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CVE-2021-23338 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.6 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C

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
0Timeline events
0ADP providers
3Source links

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
6.6CVSS 3.1MediumCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C0.75.9Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.6Medium
CVSS 3.1 vector shape for CVE-2021-23338Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H/E:P/RL:U/RC:C

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/aqlib0Listed
Weakness

CWE details

No CWE listed

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