CVE-2025-0247
Published: 07 January 2025
Summary
CVE-2025-0247 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Mozilla Firefox. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 5.4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-16 (Memory Protection) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Mandates timely identification, reporting, and patching of flaws like the memory safety bugs in Firefox 133 and Thunderbird 133 to prevent arbitrary code execution.
Implements memory safeguards such as address space layout randomization and data execution prevention to directly mitigate exploitation of memory corruption bugs like CWE-787 out-of-bounds writes.
Enables vulnerability scanning to identify and prioritize deployed instances of vulnerable Firefox 133 or Thunderbird 133 for remediation.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Memory corruption bugs enabling remote arbitrary code execution in client software (browser/email) directly map to exploitation for client execution.
NVD Description
Memory safety bugs present in Firefox 133 and Thunderbird 133. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was…
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fixed in Firefox 134 and Thunderbird 134.
Deeper analysisAI
CVE-2025-0247 encompasses multiple memory safety bugs present in Firefox 133 and Thunderbird 133. These bugs, associated with CWE-787 (Out-of-bounds Write), demonstrated evidence of memory corruption, and Mozilla presumes that with sufficient effort, some could be exploited to run arbitrary code. The vulnerability received a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), marking it as critical.
Remote attackers can exploit these bugs over the network with low attack complexity, requiring no privileges, authentication, or user interaction. Successful exploitation could result in high impacts to confidentiality, integrity, and availability, potentially allowing arbitrary code execution on affected systems.
Mozilla addressed CVE-2025-0247 in Firefox 134 and Thunderbird 134. For mitigation details, refer to Mozilla Security Advisories MFSA 2025-01 and MFSA 2025-04, along with the Bugzilla entries at https://bugzilla.mozilla.org/buglist.cgi?bug_id=1835193%2C1910021%2C1919803%2C1931576%2C1931948%2C1932173.
Details
- CWE(s)