CVE-2020-13959
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Velocity Tools XSS Vulnerability
rank 20 = 1 + 15 + 0 + 4 + 0
rank@v1 · backlog
Someone is already using it
CISA KEV catalog · public proof-of-concept · FIRST EPSS
EPSS 0.05723 · without this subject the record ranks 19
What it costs you if it fires
NVD CVSS base score, then the CNA's own
CVSS 6.1, from NVD · without this subject the record ranks 5
It is getting worse, not staying still
FIRST EPSS series, rescorings and bad loads removed
no persisting rise in 365 days · without this subject the record ranks 20
How much of the world it touches
NVD CPE configurations
2 products in the CPE ranges · without this subject the record ranks 16
Someone else already set the date
CISA KEV remediation due date
no CISA due date · without this subject the record ranks 20
$122,000 = $4.99M incident cost x 0.42806422275080447 exposure x 0.05723 likelihood
udv@v1 · unaudited · wrong for you until you say what you run
$4.99M is the cost of a breach that happened, from IBM Cost of a Data Breach Report 2026, global average. It is not the value of any asset of yours. That average already covers breaches of every severity, so scaling it by exposure understates a partial-impact record. That is an assumption, not a measurement. Your own asset value goes in the decision record.
Hindsight · the state
Foresight · where to check next
Velocity is one instance of CWE-79, improper neutralization of input during web page generation ('cross-site scripting'). The index holds 47894 prior instances of this class, 32 KEV-listed. 5 neighbors share the mechanism; each carries its own record state. taxonomy@v1
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Harm, if it fires from the vector and the weakness
Written for the ticket you're about to file.
CISA KEV & Federal Remediation Deadline from the record and CISA
The fix, and how long it's been waiting.
Exploit Status & Known PoCs a ladder, not a score
Current rung: Nothing observed in held sources.
- RUNG 1Nothing observed in held sources
- RUNG 2Proof-of-concept published
- RUNG 3Exploited in the wild · CISA KEV listed
- RUNG 4Ransomware campaign use known
A rung lights from a row in the index, never from an assessment. "Held sources" is the true scope of the claim: this index reads the CVE record, NVD, CISA KEV, FIRST's EPSS and public proof-of-concept repositories, and it does not observe attacks.
What it is stated by the CNA
The default error page for VelocityView in Apache Velocity Tools prior to 3.1 reflects back the vm file that was entered as part of the URL. An attacker can set an XSS payload file as this vm file in the URL which results in this payload being executed. XSS vulnerabilities allow attackers to execute arbitrary JavaScript in the context of the attacked website and the attacked user. This can be abused to steal session cookies, perform requests in the name of the victim or for phishing attacks. receipt
NVD's analysis a second authority
- severity
- 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- weakness
- CWE-79
- affected versions
- apache velocity tools < 3.1; debian linux 9.0
check it yourself lists.apache.org lists.apache.org lists.apache.org openwall.com lists.debian.org lists.apache.org +1 morereceipt
Dated events
Movement the material steps
This score more than doubled inside 72 hours. Both observations are in the full history below.
Show all 29 observations
29 observations held. A highlighted step crossed a promotion threshold. A step marked with a scoring model moved because the instrument was replaced, not because the vulnerability changed. receipt
The full biography
Exploit probability more than doubled between 2021-07-24 and 2021-07-25 (0.05727 → 0.21419) and the record had been public for 5 years, 5 months when this index was last written.
The pattern, elsewhere
Velocity is one instance of CWE-79, improper neutralization of input during web page generation ('cross-site scripting'). The index holds 47894 prior instances of this class, 32 KEV-listed. 5 neighbors share the mechanism; each carries its own record state. [email protected]
47894 records in this class held. The six above are ranked by exploit maturity, then recency.
Siblings and hubs
Records related to this one
None. No alias set, and nothing in the corpus cites this identifier or shares its product family within 60 days.
Browse the index from here
These are index-wide views, not findings about CVE-2020-13959.
What usually comes next
Everything above needs no account. What is below is work: assembling it, scoping it to your estate, watching it, and handing it to someone else.