Denial of Service (DoS)
Incorrect handling of Upgrade header with the value websocket leads in crashing of containers hosting sockjs apps. This affects the package sockjs before 0.3.20.
- Published
- Jul 9, 2020
- Updated
- Jun 16, 2026
- EPSS
- 5.0% · 92th percentile
- CWE
- CWE-755
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Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 5.0%
CNA vs NVD score
- NVD
- 5.3
- CNA · snyk
- 5.3
- agree
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| sockjs project | sockjs | cpe:2.3:a:sockjs_project:sockjs |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- sockjs project sockjsbefore 0.3.20
Versions reported by the vendor
Affected version ranges reported by the assigning authority (snyk). Independent of NVD's CPE analysis and usually ahead of it.
n/a sockjs
- unspecified and later · before 0.3.20affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | sockjs | before 0.3.20 | 0.3.20 |
Same product
sockjs project: all recordsOther highest-scoring records for the same primary product.
- CVE-2020-8823htmlfile in lib/transport/htmlfile.js in SockJS before 0.3.0 is vulnerable to Reflected XSS via the /htmlfile c (aka callback) parameter.25Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| npm:sockjs | 0.3.20 | Package registry (OSV) |
Exploit status
Proof of concept available
A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.
Evidence
- Proof-of-concept repository on GitHub ×2
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Proof-of-concept repository on GitHub | stars:1 | 2020-07-03 |
| Proof-of-concept repository on GitHub | stars:0 | 2026-01-13 |
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.
- First PoC-6 d
- Published
- TodaySep 30, 2026+2275 d
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
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.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-755 · Improper Handling of Exceptional ConditionsCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/sockjs/sockjs-node/commit/dd7e642cd69ee74385825816d30642c43e051d16
- github.com/sockjs/sockjs-node/pull/265
Vendor advisories and official records. Exploit/PoC links are deliberately left out.