Critical severity · published Feb 18, 2022
CVE-2021-3657
A flaw was found in mbsync versions prior to 1.4.4
9.8
CVSS
3.5%
EPSS
No
On KEV
Description
A flaw was found in mbsync versions prior to 1.4.4. Due to inadequate handling of extremely large (>=2GiB) IMAP literals, malicious or compromised IMAP servers, and hypothetically even external email senders, could cause several different buffer overflows, which could conceivably be exploited for remote code execution.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)3.5% · higher than 89% 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
EL
Enterprise Linux · Redhat
7.0 · source: NVD
FE
Fedora · Fedoraproject
35 · source: NVD
IS
Isync · Isync Project
before 1.4.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-3657
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-3657
Issue Tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2028932
Mailing List
https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
Third Party Advisory
https://security.gentoo.org/glsa/202208-15
Mailing List
https://www.openwall.com/lists/oss-security/2021/12/03/1
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