CVE-2019-9792

critical

Published 2019-05-07 · Modified 2019-05-13

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

10.0

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.

Predictions

Exploit likelihood

55%

Patch ETA

—

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-46939 dos multiple verified

Google Security Research · 2019-05-29

Spidermonkey - IonMonkey Leaks JS_OPTIMIZED_OUT Magic Value to Script

Source code queued for fetch — refresh in a moment.

OS impact

SUSE Affected 1 release

Version	Status	Fixed in
—	Affected	—

Arch Fixed 1 release

Version	Status	Fixed in
—	Fixed	`66.0-1`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`60.6.0esr-1`
sid	Fixed	`66.0-1`
forky	Fixed	`60.6.0esr-1`
bullseye	Fixed	`60.6.0esr-1`
bookworm	Fixed	`60.6.0esr-1`

Red Hat Fixed 1 release

Version	Status	Fixed in
8	Fixed	—

References

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.