CVE-2018-20201: There is a stack-based buffer over-read in the jsfNameFromString function of jsflash.c in Espruino 2V00, leadi

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HIGH 7.8MITIGATE

CVE-2018-20201 is a high-severity flaw (CVSS 7.8) affecting espruino. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

There is a stack-based buffer over-read in the jsfNameFromString function of jsflash.c in Espruino 2V00, leading to a denial of service or possibly unspecified other impact via a crafted js file.

Why this priority

High severity
Public exploit reference

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	1.1% (top 35%)
CISA exploited list	No
Weakness	CWE-125
Published	2018-12-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: pur3

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2018-12-18 09:29 UTCPublished CVE record published
2026-06-17 01:52 UTCUpdated Record last modified

pur3 espruino MITIGATE

Affected: 2.00

Fixed in: no fixed release known

Safe to downgrade to: a release before 2.00

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2018-20201?

espruino: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2018-20201 being exploited?

CVE-2018-20201 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2018-20201 affect?

CVE-2018-20201 affects espruino. Severity is high (CVSS 7.8). There is a stack-based buffer over-read in the jsfNameFromString function of jsflash.c in Espruino 2V00, leading to a denial of service or possibly unspecified other impact via a crafted js file.

How urgent is CVE-2018-20201?

Priority 49/100. High severity; Public exploit reference

Related CVEs

CVE-2024-25201 HIGH 7.5 MITIGATE Espruino 2v20 (commit fcc9ba4) was discovered to contain an Out-of-bounds Read via jsvStringIteratorPrintfCall
CVE-2024-25200 HIGH 7.5 MITIGATE Espruino 2v20 (commit fcc9ba4) was discovered to contain a Stack Overflow via the jspeFactorFunctionCall at sr
CVE-2022-25465 HIGH 7.8 MITIGATE Espruino 2v11 release was discovered to contain a stack buffer overflow via src/jsvar.c in jsvGetNextSibling.
CVE-2022-25044 HIGH 7.8 MITIGATE Espruino 2v11.251 was discovered to contain a stack buffer overflow via src/jsvar.c in jsvNewFromString.
CVE-2021-46325 HIGH 7.8 MITIGATE Espruino 2v10.246 was discovered to contain a stack buffer overflow via src/jsutils.c in vcbprintf.

References

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