CVE-2021-29945
MEDIUM
6.5
CVSS Score
Published: June 24, 2021 at 01:19 PM UTC
Updated: June 17, 2026 at 03:48 AM UTC
3 products affected across 1 vendorFirefoxThunderbirdFirefox ESR
Using Firefox ESR by Mozilla?
Get instant alerts when new vulnerabilities affect Firefox ESR - before attackers find them.
Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.5
Exploit prediction
EPSS 1%
Description
The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash. *Note: This issue only affected x86-32 platforms. Other platforms are unaffected.*. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.
Affected
Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.
v < 88v < 88.0
Affected range stops below 88, so it looks safe — our inference, not a vendor statement
Affected range stops below 88.0, so it looks safe — our inference, not a vendor statement
v < 78.10
Affected range stops below 78.10, so it looks safe — our inference, not a vendor statement
v < 78.10
Affected range stops below 78.10, so it looks safe — our inference, not a vendor statement
Remediation
No guide yetNo remediation guidance has been written for this CVE yet. What the record does show:
References (4)
x_refsource_MISCIssue TrackingPermissions RequiredVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1700690x_refsource_MISCRelease NotesVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-14/x_refsource_MISCRelease NotesVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-15/x_refsource_MISCRelease NotesVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-16/CVSS
- Attack Vector
- NETWORK
- Complexity
- LOW
- Privileges
- NONE
- User Interaction
- REQUIRED
- Scope
- UNCHANGED
- Confidentiality
- NONE
- Integrity
- NONE
- Availability
- HIGH
Vector?
Quick Info
StatusMODIFIED
CWE
CWE-682
Get alerted
Stop reading CVE feeds looking for your own stack
Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.
Free plan, no card