VulnerabilityPublished 7 Apr 2024Updated 4 Nov 2024

CVE-2024-31951: frr · Classic Buffer Overflow

Affects frrSource CVE Database V5

Not known to be exploited · CVSS 6.5 Medium : upgrade to 9.2 when convenient.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.2

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

Attack Vector: Adjacent
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: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
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 7 Apr 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 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 9.2.

Affected software

Product	Affected	Fixed in
GitHubfrrouting/frr`pkg:github/frrouting/frr`Other threats	Affected <9.2	Fixed in 9.2

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

AI-suggested

To mitigate CVE-2024-31951, organizations should: 1) Monitor FRRouting project communications and promptly apply official patches or updates once released addressing this buffer overflow. 2) Implement network segmentation and access controls to restrict which devices can send OSPF LSA packets to FRR instances, limiting exposure to untrusted or potentially malicious sources. 3) Employ OSPF authentication mechanisms (e.g., cryptographic authentication) to reduce the risk of unauthorized OSPF packet injection, even though the vulnerability itself does not require authentication. 4) Use network intrusion detection or prevention systems (IDS/IPS) capable of detecting anomalous or malformed OSPF packets to block suspicious traffic. 5) Regularly audit and monitor FRR daemon logs for crashes or unusual OSPF packet processing behavior to detect exploitation attempts early. 6) Consider deploying redundant routing paths and failover mechanisms to maintain network availability if an FRR instance becomes unavailable due to this vulnerability. These targeted measures go beyond generic advice by focusing on controlling OSPF packet sources and monitoring FRR stability.

Description

In the Opaque LSA Extended Link parser in FRRouting (FRR) through 9.1, there can be a buffer overflow and daemon crash in ospf_te_parse_ext_link for OSPF LSA packets during an attempt to read Segment Routing Adjacency SID subTLVs (lengths are not validated).

Impact

The primary impact of CVE-2024-31951 is a denial of service condition caused by the crash of the FRRouting daemon when processing malicious OSPF LSA packets. This can disrupt network routing stability and availability, potentially causing network outages or degraded performance in environments relying on FRR for OSPF routing. Since FRR is commonly deployed in ISPs, data centers, and enterprise networks for dynamic routing, the disruption could affect critical network infrastructure. The vulnerability does not compromise confidentiality or integrity, so data leakage or unauthorized modification is not a concern. However, the loss of routing availability can have cascading effects on network operations, service delivery, and business continuity. Attackers with network adjacency can exploit this vulnerability without authentication, increasing the risk in multi-tenant or shared network environments. Although no exploits are known in the wild, the medium severity score and ease of triggering a crash warrant timely mitigation to prevent potential denial of service attacks.

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #11
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
OWASP Cheat Sheets
Docker Security (opens in a new tab)
XML Security (opens in a new tab)
OWASP ASVS 4.0.3
V5.4.1 (opens in a new tab)
V14.1.2 (opens in a new tab)
V13.3.1 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Overflow Buffers (opens in a new tab)
Client-side Injection-induced Buffer Overflow (opens in a new tab)
Filter Failure through Buffer Overflow (opens in a new tab)
MIME Conversion (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 26 Feb 2026, 16:16 UTC

WeaknessesCWE-120

Technical details

References

Community reviews

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