Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-3578

26
FAUCET Score

CVE-2021-3578 is a critical vulnerability affecting mbsync versions prior to v1.3.6 and v1.4.2, impacting various Debian and Fedora distributions of isync. The flaw, an unchecked pointer cast, allows a malicious or compromised server to write arbitrary integer values beyond a heap-allocated structure via an unexpected APPENDUID response. This vulnerability carries a high CVSS score of 7.8, indicating a low attack complexity and the potential for remote code execution, leading to high impacts on confidentiality, integrity, and availability. Currently, there is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
< 1.3.6CPE matchmatch criteria
cpe:2.3:a:isync_project:isync:*:*:*:*:*:*:*:*
1.4.0CPE matchmatch criteria
cpe:2.3:a:isync_project:isync:1.4.0:*:*:*:*:*:*:*
1.4.1CPE matchmatch criteria
cpe:2.3:a:isync_project:isync:1.4.1:*:*:*:*:*:*:*
33CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
34CPE matchmatch criteria
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

7.8HIGH

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

Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
1.8
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
1.04%
Probability of exploitation in next 30 days
EPSS Percentile
60.4%
Percentile rank of EPSS score among Peer Group
As of 2026-07-28
Model: v2026.06.15
This CVE's current EPSS score of 0.0104 is in the 92nd percentile among its peer group of 17,070 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.2 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (1)

redhatpatch availablevia nvd_reference
View patch

References

bugzilla.redhat.com / show_bug.cgi
Not Applicable
bugzilla.redhat.com / show_bug.cgi
Issue TrackingPatchThird Party Advisory
github.blog / 2021-06-10-privilege-escalation-polkit-root-on-linux-with-bug
Not Applicable
lists.debian.org / debian-lts-announce/2022/07/msg00001.html
Mailing ListThird Party Advisory
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/RPIDLIJKNRJHUVBCL7QGAPAAVPIHQGXK
lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/U75UFEWRAZYKVL5NHMPBUOLWN3WXTOEI
security.gentoo.org / glsa/202208-15
Third Party Advisory
openwall.com / lists/oss-security/2021/06/07/1
Mailing ListPatchThird Party Advisory
openwall.com / lists/oss-security/2021/06/07/1
Mailing ListPatchThird Party Advisory