LF Edge eKuiper: Self-XSS in External Service Creation
Summary
A Cross-Site Scripting (XSS) vulnerability in external service creation allows an authenticated attacker to inject HTML/script payloads into external service names, which may execute in a user's browser when rendered by administrative web interfaces.
Details
Prior to v2.4.0, external service registration endpoints did not strictly enforce alphanumeric character restrictions on service names. An operator or attacker with API access could register a service using a crafted name containing HTML elements (such as `
). If an administrative web UI rendered the unescaped service name, arbitrary script execution could occur in the context of the user's browser session.PoC
- Create an external service JSON definition with a filename containing an XSS payload, e.g.
.json
inside a ZIP archive.
In external service creation, upload the ZIP and provide the matching service name: .
Upon service registration, the unescaped name executes when rendered in the UI context.Impact
Self-XSS / Stored XSS leading to potential session token leakage or unauthorized actions in the context of the affected user's browser session.Remediation & Patches
- Upgrade to eKuiper >= 2.4.0: Strict alphanumeric identifier validation (
validate.ValidateID
) is now enforced on all external service creation and update endpoints, rejecting invalid characters.Workarounds
- Protect eKuiper management endpoints (
POST /services`) with authentication and network-level firewalls.
Credits
- Reported by Alexey Kosmachev, Bi.Zone (@TheMostKnown)
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (3.7): severity, escalated by confirmed exploitation. This CVE's 3.7 is its impact severity (EG Severity), not escalated.
- EG Severity
- 3.7 LOWCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it