CVE-2018-12383

CVE-2018-12383 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-522.

Key facts

Description

If a user saved passwords before Firefox 58 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Firefox 58. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations. This vulnerability affects Firefox < 62, Firefox ESR < 60.2.1, and Thunderbird < 60.2.1.

Frequently asked questions

What is CVE-2018-12383?
If a user saved passwords before Firefox 58 and then later set a master password, an unencrypted copy of these passwords is still accessible. This is because the older stored password file was not deleted when the data was copied to a new format starting in Firefox 58. The new master password is added only on the new file. This could allow the exposure of stored password data outside of user expectations. This vulnerability affects Firefox < 62, Firefox ESR < 60.2.1, and Thunderbird < 60.2.1.
How severe is CVE-2018-12383?
CVE-2018-12383 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2018-12383 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-12383?
CVE-2018-12383 primarily affects Mozilla Firefox. In total, 18 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-12383?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-12383 published?
CVE-2018-12383 was published on 2018-10-18 and last updated on 2026-06-17.

References

Affected products (18)

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