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CVE-2021-29978

30
FAUCET Score

CVE-2021-29978 describes multiple low-security issues identified in Mozilla VPN 2.x branch during a third-party security audit, affecting versions prior to 2.3. This vulnerability carries a critical CVSS score of 9.8, indicating a network-exploitable flaw with low attack complexity that could lead to complete compromise of confidentiality, integrity, and availability. Despite its high severity, there is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.

Impacted Technologies

VendorProductVersion(s)CPE
>= 2.0, < 2.3CPE matchmatch criteria
cpe:2.3:a:mozilla:mozilla_vpn:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

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

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
2.78%
Probability of exploitation in next 30 days
EPSS Percentile
84.9%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0278 is in the 76th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 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 (2)

github_advisorypatch availablevia nvd_reference
View patch
mozillavendor investigatingvia nvd_reference
View patch

References

github.com / mozilla-mobile/mozilla-vpn-client/issues/797
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/798
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/799
ExploitThird Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/800
ExploitThird Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/801
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/803
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/804
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/805
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/806
ExploitThird Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/808
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/809
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/810
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/issues/812
Third Party Advisory
github.com / mozilla-mobile/mozilla-vpn-client/pull/816
PatchThird Party Advisory
mozilla.org / security/advisories/mfsa2021-31
Vendor Advisory