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CVE Record

CVE-2021-4253: ctrlo lenio Ticket Lenio.pm cross site scripting

A vulnerability, which was classified as problematic, was found in ctrlo lenio. Affected is an unknown function in the library lib/Lenio.pm of the component Ticket Handler. The manipulation of the argument site_id leads to cross site scripting. It is possible to launch the attack remotely. The name of the patch is 7a1f90bd2a0ce95b8338ec0926902da975ec64d9. It is recommended to apply a patch to fix this issue. VDB-216210 is the identifier assigned to this vulnerability.

LowCVSS 3.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

CVE-2021-4253 is a low-severity cross-site scripting issue in ctrlo lenio's Ticket Handler. A manipulated site_id value could cause a user-facing script injection path. The published scoring indicates limited integrity impact, no confidentiality or availability impact, and required user interaction.

Executive priority

Treat this as routine remediation unless lenio is internet-facing or used in sensitive workflows. The business risk is mainly user-interface trust and limited data integrity, not system takeover, based on the provided CVSS and references.

Technical view

The issue affects lib/Lenio.pm in ctrlo lenio's Ticket Handler. The source bundle says manipulating site_id leads to cross-site scripting and remote attack is possible. CVSS 3.1 is 3.5, with network access, low attack complexity, low privileges required, and user interaction required.

Likely exposure

Exposure is limited to organizations running ctrlo lenio with the vulnerable Ticket Handler code. The affected version range is not specified in the source bundle, so confirm by repository state or vendor guidance rather than assuming all releases are affected.

Exploitation context

The source bundle does not show KEV listing or active exploitation. Exploitation is described as remote, but CVSS indicates an attacker needs low privileges and user interaction. No exploit steps should be inferred from the available evidence.

Researcher notes

Key evidence gaps are the unspecified affected versions and unknown function name. The patch reference is specific, but the source bundle does not provide detailed root-cause analysis, exploit maturity, or confirmed exploitation telemetry.

Mitigation direction

  • Apply the upstream patch commit 7a1f90bd2a0ce95b8338ec0926902da975ec64d9.
  • Check ctrlo lenio vendor or repository guidance for affected version details.
  • Limit access to the Ticket Handler where operationally possible.
  • Review any local forks for equivalent site_id handling.

Validation and detection

  • Inventory whether ctrlo lenio is deployed in your environment.
  • Verify lib/Lenio.pm includes the referenced patch changes.
  • Confirm Ticket Handler routes are not exposed beyond intended users.
  • Run XSS regression tests around site_id rendering and validation.
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

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ATT&CK lookup starting points

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cwe · low confidence lookup

CWE-707: Exact CWE lookup

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cve · low confidence lookup

CVE-2021-4253 mapping review

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Vulnerability profileCVE Program record
Severity
Low
CVSS
3.5 (3.1)
Known Exploited
No
Published

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

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
3.5CVSS 3.1LowCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N2.11.4Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

3.5Low
CVSS 3.1 vector shape for CVE-2021-4253Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

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

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
ctrlolenion/aListed
Weakness

CWE details

CWE-707

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