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CVE-2021-29986

HIGH
8.1
CVSS Score
Published: August 17, 2021 at 07:12 PM UTC
Updated: June 17, 2026 at 03:48 AM UTC
3 products affected across 1 vendorFirefoxThunderbirdFirefox ESR· also runs on 1 platform

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Severity
HIGH8.1
Exploit prediction
EPSS 1%

Description

A suspected race condition when calling getaddrinfo led to memory corruption and a potentially exploitable crash. *Note: This issue only affected Linux operating systems. Other operating systems are unaffected.* This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Affected

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

Firefox· Mozilla
95%
v < 91
Affected range stops below 91, so it looks safe — our inference, not a vendor statement
Affected range stops below 91.0, so it looks safe — our inference, not a vendor statement
linux-linux-kernel (environment)
Firefox ESR· Mozilla
95%
v < 78.13
Affected range stops below 78.13, so it looks safe — our inference, not a vendor statement
Affected range stops below 78.13.0, so it looks safe — our inference, not a vendor statement
linux-linux-kernel (environment)
Thunderbird· Mozilla
95%
v < 78.13v < 91
Affected range stops below 78.13, so it looks safe — our inference, not a vendor statement
Affected range stops below 78.13.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 91, so it looks safe — our inference, not a vendor statement
linux-linux-kernel (environment)

Runs on — not affected

The affected product only carries this flaw when running on these platforms. The platforms themselves are not vulnerable.

References (7)

x_refsource_MISCExploitIssue TrackingVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1696138
Vendor Advisoryx_refsource_GENTOOThird Party Advisory
Source: [email protected]
https://security.gentoo.org/glsa/202202-03
Vendor Advisoryx_refsource_GENTOOThird Party Advisory
Source: [email protected]
https://security.gentoo.org/glsa/202208-14
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-33/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-34/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-35/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2021-36/

CVSS

8.1HIGH[email protected]
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-362

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