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CVE-2019-9792

CRITICAL
9.8
CVSS Score
Published: April 26, 2019 at 04:13 PM UTC
Updated: June 17, 2026 at 02:44 AM UTC
7 products affected across 2 vendorsFirefoxEnterprise LinuxThunderbird

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Severity
CRITICAL9.8
Exploit prediction
EPSS 13%

Description

The IonMonkey just-in-time (JIT) compiler can leak an internal JS_OPTIMIZED_OUT magic value to the running script during a bailout. This magic value can then be used by JavaScript to achieve memory corruption, which results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

Affected

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

Firefox· Mozilla
95%
v < 60.6.0v < 66v < 66.0
Affected range stops below 66, so it looks safe — our inference, not a vendor statement
Affected range stops below 66.0, so it looks safe — our inference, not a vendor statement
Thunderbird· Mozilla
95%
v < 60.6v < 60.6.0
Affected range stops below 60.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 60.6.0, so it looks safe — our inference, not a vendor statement
Enterprise Linux· Red Hatrpm
95%
8.0
Enterprise Linux Eus· Red Hatrpm
95%
8.18.28.4
Enterprise Linux Server Aus· Red Hatrubygems
95%
8.28.4
Enterprise Linux Server Tus· Red Hatrubygems
95%
8.28.4
Firefox ESR· Mozilla
60%
v < 60.6
Affected range stops below 60.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 60.6.0, so it looks safe — our inference, not a vendor statement

References (7)

x_refsource_MISCExploitThird Party AdvisoryVDB Entry
Source: [email protected]
http://packetstormsecurity.com/files/153106/Spidermonkey-IonMonkey-JS_OPTIMIZED_OUT-Value-Leak.html
Vendor Advisoryx_refsource_REDHATThird Party Advisory
Source: [email protected]
https://access.redhat.com/errata/RHSA-2019:0966
Vendor Advisoryx_refsource_REDHATThird Party Advisory
Source: [email protected]
https://access.redhat.com/errata/RHSA-2019:1144
x_refsource_MISCExploitIssue TrackingVendor Advisory
Source: [email protected]
https://bugzilla.mozilla.org/show_bug.cgi?id=1532599
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2019-07/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2019-08/
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.mozilla.org/security/advisories/mfsa2019-11/

CVSS

9.8CRITICAL[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-787

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