High severity · published Feb 23, 2021
CVE-2021-20247
A flaw was found in mbsync before v1.3.5 and v1.4.1
7.4
CVSS
1.9%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.9% · higher than 79% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0 · source: NVD
EP
Extra Packages For Enterprise Linux · Fedoraproject
8.0 · source: NVD
FE
Fedora · Fedoraproject
32; 33 · source: NVD
MB
Mbsync · Mbsync Project
before 1.3.5; 1.4.0 before 1.4.1 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-20247
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-20247
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=1928963
Mailing List
https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CAXQLCK35QGRCRENRTGKJO4VVZGUXUJJ/
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDEBZQJMWDW5JFK4NTHH6DAFNAZTESW/
Third Party Advisory
https://security.gentoo.org/glsa/202208-15
Exploit
https://www.openwall.com/lists/oss-security/2021/02/22/1
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