CVE-2024-56375VulnerabilityPublished 22 Dec 2024Updated 6 Jan 2025

CVE-2024-56375: nicmx fort-validator · Integer Underflow (Wrap or Wraparound)

Affects nicmx fort-validatorSource CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 22 Dec 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 2026-10-25.

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

Affected software

Product	Affected	Fixed in
GitHubnicmx/fort-validator`pkg:github/nicmx/fort-validator`Other threats	Affected =1.6.3	Fixed in–

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AI-suggested

To mitigate CVE-2024-56375, organizations should immediately upgrade fort-validator to version 1.6.5 or later, where the integer underflow and associated infinite loop have been fixed. Until an upgrade is possible, administrators should consider implementing network-level filtering to restrict access to RPKI repository synchronization endpoints (rsync and RRDP) to trusted sources only, reducing exposure to malicious repositories. Monitoring fort-validator logs and system health for signs of crashes or infinite loops can provide early detection of exploitation attempts. Additionally, validating the integrity and correctness of RPKI repository data before processing can help prevent malformed manifests from triggering the vulnerability. Organizations should also maintain up-to-date backups and failover mechanisms for RPKI validation services to minimize downtime. Engaging with the fort-validator vendor or community for patches and advisories is recommended.

Description

An integer underflow was discovered in Fort 1.6.3 and 1.6.4 before 1.6.5. A malicious RPKI repository that descends from a (trusted) Trust Anchor can serve (via rsync or RRDP) a Manifest RPKI object containing an empty fileList. Fort dereferences (and, shortly afterwards, writes to) this array during a shuffle attempt, before the validation that would normally reject it when empty. This out-of-bounds access is caused by an integer underflow that causes the surrounding loop to iterate infinitely. Because the product is permanently stuck attempting to overshuffle an array that doesn't actually exist, a crash is nearly guaranteed.

Impact

The primary impact of CVE-2024-56375 is a denial of service condition on fort-validator instances used in RPKI validation. Organizations relying on fort-validator for validating RPKI data may experience service outages or disruptions in routing security validation, potentially leading to degraded network security posture. This can affect ISPs, internet exchange points, and enterprises that depend on RPKI to prevent route hijacking and misconfigurations. The vulnerability does not directly compromise confidentiality or integrity but undermines availability, which can indirectly increase the risk of routing attacks if validation services are unavailable. Since fort-validator is a critical component in the RPKI ecosystem, widespread exploitation could disrupt internet routing security infrastructure, especially in regions with heavy RPKI adoption. The ease of remote exploitation without authentication increases the risk of automated attacks causing outages.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 02:12 UTC

WeaknessesCWE-191

Technical details

References

Community reviews

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