VulnerabilityPublished 2 Jun 2023Updated 27 May 2025

CVE-2023-32213: Mozilla Firefox · Potential memory corruption in FileReader::DoReadData()

Affects Mozilla FirefoxSource CVE Database V5

Not known to be exploited : upgrade to 113 or 102.11 soon.

Data as of 26 Oct 2026, 11:07 UTC

Severity

High

Rated High by the CNA (mozilla) · No CVSS score from NVD or the CNA

EPSS: 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 113, 102.11

Exploitation evidence

Disclosed: evidence found.
CVE published 2 Jun 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Mozilla Firefox to 113 or 102.11.

Affected software

Product	Affected	Fixed in
Mozilla Firefox	Affected <113 <102.11	Fixed in 113 102.11

AI-suggested

European organizations should prioritize updating affected Mozilla products to the fixed versions: Firefox 113 or later, Firefox ESR 102.11 or later, and Thunderbird 102.11 or later. If you cannot patch yet, organizations should consider implementing strict content security policies to limit exposure to untrusted web content that might exploit the FileReader API. Disabling or restricting the use of the FileReader API in enterprise browser configurations could reduce attack surface, though this may impact functionality. Email filtering solutions should be enhanced to detect and block malicious attachments that could trigger the vulnerability in Thunderbird. Network-level protections such as web proxies and sandboxing of browser sessions can help contain potential exploitation attempts. Continuous monitoring for unusual application crashes or behavior in Firefox and Thunderbird instances should be established to detect potential exploitation attempts early. Finally, organizations should educate users about the risks of opening untrusted files or links, as user interaction may be required to trigger the vulnerability.

Description

When reading a file, an uninitialized value could have been used as read limit. This vulnerability affects Firefox < 113, Firefox ESR < 102.11, and Thunderbird < 102.11.

Impact

For European organizations, the impact of CVE-2023-32213 could be substantial due to the widespread use of Firefox and Thunderbird in both corporate and governmental environments. Exploitation could lead to unauthorized code execution, allowing attackers to compromise user systems, steal sensitive information, or disrupt operations. This is especially critical for sectors handling sensitive data such as finance, healthcare, and public administration. The vulnerability could be exploited through malicious files or web content, potentially delivered via phishing campaigns or compromised websites. Given that Thunderbird is also affected, email remains a vector for attack, increasing risk exposure. Organizations relying on Firefox ESR for stability and security updates may be particularly vulnerable if they have not yet applied the 102.11 update. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability details become widely known. Additionally, the memory corruption nature of the flaw could lead to denial of service conditions, impacting availability of critical services.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Jul 2025, 03:10 UTC

Technical details

References

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