How severe is CVE-2017-1000420?

CVE-2017-1000420 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2017-1000420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-1000420?

CVE-2017-1000420 affects Syncthing. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-1000420?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-1000420 published?

CVE-2017-1000420 was published on 2018-01-02 and last updated on 2026-06-17.

CVE-2017-1000420

CVE-2017-1000420 is a high-severity vulnerability in Syncthing with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-59.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 6.4
EPSS exploit prediction: 2% (71st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Syncthing
Published: 2018-01-02
Last modified: 2026-06-17

Description

Syncthing version 0.14.33 and older is vulnerable to symlink traversal resulting in arbitrary file overwrite

Frequently asked questions

What is CVE-2017-1000420?: Syncthing version 0.14.33 and older is vulnerable to symlink traversal resulting in arbitrary file overwrite
How severe is CVE-2017-1000420?: CVE-2017-1000420 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2017-1000420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-1000420?: CVE-2017-1000420 affects Syncthing. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-1000420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-1000420 published?: CVE-2017-1000420 was published on 2018-01-02 and last updated on 2026-06-17.

References

https://github.com/syncthing/syncthing/issues/4286

Affected products (1)

cpe:2.3:a:syncthing:syncthing:*:*:*:*:*:*:*:*

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