VulnerabilityPublished 6 Nov 2023Updated 4 Nov 2025

CVE-2023-38407: frr

Affects frrSource CVE Database V5

Not known to be exploited · CVSS 7.5 High : upgrade to 8.5 soon.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.9% chance of exploitation in 30 days – higher than 60% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 8.5

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 6 Nov 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 frrouting/frr to 8.5.

Affected software

Product	Affected	Fixed in
GitHubfrrouting/frr`pkg:github/frrouting/frr`Other threats	Affected <8.5	Fixed in 8.5

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The most effective mitigation is to upgrade FRRouting to version 8.5 or later, where this vulnerability has been addressed. Until patching is possible, network administrators should implement strict filtering of incoming BGP labeled unicast messages from untrusted sources to reduce exposure. Monitoring the stability and logs of the bgpd daemon can help detect attempts to exploit this vulnerability. Employing network segmentation and limiting BGP peering to trusted partners reduces the attack surface. Additionally, organizations should maintain up-to-date backups of router configurations and have incident response plans ready to quickly recover from potential outages. Coordinating with upstream providers and peers to ensure they are also patched can help prevent exploitation through external BGP sessions.

Description

bgpd/bgp_label.c in FRRouting (FRR) before 8.5 attempts to read beyond the end of the stream during labeled unicast parsing.

Impact

For European organizations, the primary impact of CVE-2023-38407 is the potential disruption of network routing services due to BGP daemon crashes. This can lead to temporary loss of connectivity, routing instability, and degraded network performance. Telecommunications providers, internet service providers (ISPs), and large enterprises using FRRouting for BGP routing are at risk of service outages, which could affect customers and critical infrastructure. The denial of service could also be leveraged as part of a broader attack to degrade network availability or as a distraction for other malicious activities. Given the reliance on FRR in many European network environments, the vulnerability poses a significant operational risk, especially in countries with advanced internet exchange points and dense network interconnections.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 4 Nov 2025, 16:51 UTC

Technical details

References

Community reviews

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