CVE-2020-6821

HIGH

7.5

CVSS Score

Published: April 24, 2020 at 03:55 PM UTC

Updated: June 17, 2026 at 03:23 AM UTC

3 products affected across 1 vendorFirefoxThunderbirdFirefox ESR

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Severity

HIGH7.5

Exploit prediction

EPSS 2%

Description

When reading from areas partially or fully outside the source resource with WebGL's <code>copyTexSubImage</code> method, the specification requires the returned values be zero. Previously, this memory was uninitialized, leading to potentially sensitive data disclosure. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firefox · Mozilla

95%

v < 75

Affected range stops below 75, so it looks safe — our inference, not a vendor statement

Affected range stops below 75.0, so it looks safe — our inference, not a vendor statement

Firefox ESR · Mozilla

95%

v < 68.7

Affected range stops below 68.7, so it looks safe — our inference, not a vendor statement

Affected range stops below 68.7.0, so it looks safe — our inference, not a vendor statement

Thunderbird · Mozilla

95%

v < 68.7.0

Affected range stops below 68.7.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (5)

x_refsource_MISCIssue TrackingPermissions Required

Source: [email protected]

https://bugzilla.mozilla.org/show_bug.cgi?id=1625404

Vendor Advisoryx_refsource_UBUNTUThird Party Advisory

Source: [email protected]

https://usn.ubuntu.com/4335-1/

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-12/

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-13/

x_refsource_MISCVendor Advisory

Source: [email protected]

https://www.mozilla.org/security/advisories/mfsa2020-14/

CVSS

7.5HIGH[email protected]

Attack Vector: NETWORK
Complexity: LOW
Privileges: NONE
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: NONE
Availability: NONE

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-908

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