Vulnerability report

Exploited in the wild High confidence Not in CISA KEV

CVE-2021-48017

BSCW Server Path Traversal

OrbiTeam / BSCW Server · affected before 5.2.5

Watch CVE-2021-48017 Browse KEV feed
Severity
CVSS 8.7 · High
Confidence
High
Exploit status
Exploited in the wild
EPSS
0.4%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2021-48017 is an unauthenticated vulnerability affecting OrbiTeam BSCW Server. OrbiTeam BSCW Server 5.x before 5.2.5 and 7.x before 7.4.4 contains an unauthenticated path traversal vulnerability in the style_name...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.

Who is affected?

OrbiTeam / BSCW Server affected before 5.2.5.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

BSCW Server Path Traversal

OrbiTeam BSCW Server 5.x before 5.2.5 and 7.x before 7.4.4 contains an unauthenticated path traversal vulnerability in the style_name parameter of the theme operation. Attackers can send GET requests to /pub/bscw.cgi/?op=theme with ../ sequences in style_name to read local files such as /etc/passwd.

Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-22.

OrbiTeam Affected
BSCW Server
Before 5.2.5 Before 7.4.4
View vendor advisory (opens in new tab)
Published
22 Oct 2026
Exploitation Reported
22 Oct 2026
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

CVE References

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CVE

Recorded 22 Oct 2026

A trusted third party reported exploitation.

Proof of concept available

CVE

Recorded 22 Oct 2026

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CVE First 2026-10-22 11:10 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Scanner coverage

No scanner integrations recorded yet.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

No detection artifacts or sensor request patterns are available for this CVE yet.

Check back as sensor telemetry and scanner integrations are updated.

Risk and context

Severity, weaknesses, and research context

CVSS v4.0

8.7 High

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

0.4%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE-22

All CVSS Scores

CVSS v4.0 8.7 High

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

CVSS v3.1 7.5 High

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

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Packet Storm 165156

cve · Created Unknown

Archived SEC Consult SA-20211202-0

cve · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 11:10 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 11:10 UTC

    Added to Previdian KEV Feed

    High-confidence, third-party attested exploitation

  3. 10:57 UTC

    CVE published

    Vulnerability disclosed publicly

  4. 20:25 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2021-48017

Sample API response 
{
  "cve_id": "CVE-2021-48017",
  "confidence": "High",
  "cvss_score": 8.7,
  "cvss_estimated": false,
  "epss_score": 0.00428,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}