VulnerabilityPublished 9 Jul 2024Updated 30 Oct 2025

CVE-2024-6601: Mozilla Firefox · CWE-367

Affects Mozilla FirefoxSource CVE Database V5

Not known to be exploited · CVSS 4.7 Medium : upgrade to 128 or 115.13 when convenient.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

4.7Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 32% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 128, 115.13

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Jul 2024
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 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 128 or 115.13.

Affected software

Product	Affected	Fixed in
Mozilla Firefox	Affected <128 <115.13	Fixed in 128 115.13

AI-suggested

1. 2. Implement strict Content Security Policies (CSP) to limit the ability of cross-origin content to execute or access sensitive data. 3. Restrict browser extensions and plugins to trusted sources only, as these could be vectors to exploit the race condition. 4. Employ network-level protections such as web filtering and intrusion detection systems to identify and block suspicious web traffic that may attempt to exploit this vulnerability. 5. Educate users about the risks of running outdated browsers and the importance of applying updates promptly. 6. For high-security environments, consider using browser sandboxing or isolation technologies to limit the impact of any potential compromise. 7. Review and harden privilege management policies on endpoints to reduce the likelihood that an attacker can achieve the high privileges required for exploitation. 8. Conduct internal vulnerability assessments and penetration tests focusing on browser security to identify potential exploitation paths.

Description

A race condition could lead to a cross-origin container obtaining permissions of the top-level origin. This vulnerability affects Firefox < 128, Firefox ESR < 115.13, Thunderbird < 115.13, and Thunderbird < 128.

Impact

For European organizations, this vulnerability poses risks primarily in environments where Firefox or Thunderbird are used extensively, especially in sectors handling sensitive or regulated data such as finance, government, healthcare, and critical infrastructure. Exploitation could allow attackers to bypass same-origin policy restrictions, leading to unauthorized access to confidential information, session hijacking, or manipulation of web content integrity. The requirement for high privileges to exploit somewhat limits the attack surface but does not eliminate risk, particularly in scenarios involving insider threats or compromised user accounts. The vulnerability could also be leveraged in sophisticated phishing or web-based attacks to escalate privileges within the browser context. Given the widespread use of Firefox in Europe, especially in countries with strong privacy and open-source software adoption like Germany, France, and the Netherlands, the impact could be significant if exploited at scale. Additionally, organizations relying on Thunderbird for email communications may face risks of unauthorized access or data leakage. The medium severity rating reflects moderate risk but underscores the need for timely remediation to prevent potential exploitation.

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition (opens in a new tab)
Base weaknessLikelihood of exploit: Medium
The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
Implementation
The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation
When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design
Limit the interleaving of operations on files from multiple processes.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
OWASP ASVS 4.0.3
V1.11.3 (opens in a new tab)
V11.1.6 (opens in a new tab)
V1.11.2 (opens in a new tab)
Attack patterns
Leveraging Race Conditions via Symbolic Links (opens in a new tab)
Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2025, 16:45 UTC

WeaknessesCWE-367

Technical details

References

Community reviews

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