Is CVE-2021-20247 in the CISA KEV catalog?

No. CVE-2021-20247 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-20247?

CVE-2021-20247 has a CVSS v3 base score of 7.4 (HIGH).

What is the EPSS score for CVE-2021-20247?

CVE-2021-20247 has an EPSS score of 1.88% (77th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-20247?

Upgrade isync on debian 11 to 1.3.0-2.1 or later.

CVE & CISA-KEV Catalog

CVE-2021-20247

HIGHEPSS 77th pctl

7.4

CVSS v3

NVD

Description

A flaw was found in mbsync before v1.3.5 and v1.4.1. Validations of the mailbox names returned by IMAP LIST/LSUB do not occur allowing a malicious or compromised server to use specially crafted mailbox names containing '..' path components to access data outside the designated mailbox on the opposite end of the synchronization channel. The highest threat from this vulnerability is to data confidentiality and integrity.

CWE-20Improper Input Validation CWE-22Path Traversal

How to fix

Remediation Available

isyncDebian

Fixed in:1.3.0-2.1CVE-2021-20247

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploit Intelligence

1.88%probability of exploitation in 30 days

77thpercentile

Elevated risk: more likely to be exploited than 77% of all known CVEs.

References

Exploit1

openwall.com

Third-Party Advisory3

Other references2

Related Vulnerabilities

Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-3400	Critical	10.0	100%	KEV + Ransom	-
CVE-2021-45105	Medium	5.9	100%	-	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2018-7600	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2020-3452	High	7.5	100%	KEV	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.