NVD / CVE Program· CNA mitre

CVE-2020-26173: An incorrect access control implementation in Tangro Business Workflow before 1.18.1 allows an attacker to download documents (PDF) by…

MediumCVSS 4.3 · v3.1—No exploit No fix recorded

Noroxi assessment

Priority: Monitor (action score 17/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.74% (FIRST EPSS); higher than 55% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

An incorrect access control implementation in Tangro Business Workflow before 1.18.1 allows an attacker to download documents (PDF) by providing a valid document ID and token. No further authentication is required.

Auth bypass

Published: Dec 18, 2020
Updated: Jun 16, 2026
EPSS: 0.7% · 55th percentile
CWE: CWE-306

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 17 / 40 · 4.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.7%

CNA vs NVD score

NVD: 4.3
CNA · mitre: 3.1; 1.2 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
tangro	business workflow	cpe:2.3:a:tangro:business_workflow

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

tangro business workflowbefore 1.18.1

Same product

tangro: all records

Other highest-scoring records for the same primary product.

CVE-2020-26174tangro Business Workflow before 1.18.1 requests a list of allowed filetypes from the server and restricts uploads to the filetypes…
35Monitor
CVE-2020-26175In tangro Business Workflow before 1.18.1, an attacker can manipulate the value of PERSON in requests to /api/profile in order to change…
26Monitor
CVE-2020-26172Every login in tangro Business Workflow before 1.18.1 generates the same JWT token, which allows an attacker to reuse the token when a…
26Monitor

Published before and after this one in the same product

← EarlierCVE-2020-26171Dec 18, 2020 · In tangro Business Workflow before 1.18.1, the documentId of attachment uploads to /api/document/attachments/upload can be manipulated.
17Monitor
Later →CVE-2020-26176Dec 18, 2020 · An issue was discovered in tangro Business Workflow before 1.18.1.
17Monitor
Later →CVE-2020-26177Dec 18, 2020 · In tangro Business Workflow before 1.18.1, a user's profile contains some items that are greyed out and thus are not intended to be edited…
17Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

CVE-2020-261740 days aparttangro Business Workflow before 1.18.1 requests a list of allowed filetypes from the server and restricts uploads to the filetypes…
35Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: low · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: Low
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

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

nvd-primary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team
2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {
2  app.post(
3    "/maintenance/reset",
4    requireSession, requireRole("admin"), resetDevice
5  );
6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

www.tangro.de/

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records