Firefox: Access of Memory Location Before Start of Buffer
CVE-2024-5700 is a high-severity access of memory location before start of buffer vulnerability in Firefox from Mozilla, with a CVSS 3.1 base score of 7.0 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 127 as the first without the flaw, so updating Firefox to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.44% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Firefox to 127 or a later version.
- Update Firefox ESR to 115.12 or a later version.
- Update Thunderbird to 115.12 or a later version.
- Read the advisory on mozilla.org for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Mozilla | Firefox | before 127 | 127 |
| Mozilla | Firefox ESR | before 115.12 | 115.12 |
| Mozilla | Thunderbird | before 115.12 | 115.12 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
Memory safety bugs present in Firefox 126, Firefox ESR 115.11, and Thunderbird 115.11. 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 affects Firefox < 127, Firefox ESR < 115.12, and Thunderbird < 115.12.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Access of Memory Location Before Start of Buffer
The product reads or writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.
More Access of Memory Location Before Start of Buffer vulnerabilities (CWE-786)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in Firefox
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Recent Access of Memory Location Before Start of Buffer vulnerabilities
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