Buffer overflow in Isync Project
CVE-2021-3657
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.035 (88.7th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 88.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.035 · newest: 0.035 · change: +0.000
Affected products
- Isync Project
- Debian Linux — versions 9.0
- Fedoraproject Fedora — versions 35
- Red Hat Enterprise Linux — versions 7.0
- Isync — versions isync 1.4.4
Weakness classification (CWE)
References
- bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
- www.openwall.com/lists/oss-security/2021/12/03/1 (Mailing List, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2022/07/msg00001.html (mailing-list, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202208-15 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-3657?
- CVE-2021-3657 is a critical-severity vulnerability in Isync Project, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2022-02-18.
- How severe is CVE-2021-3657?
- Critical severity. CVSS v3 base score is 9.8 out of 10.