CVE-2025-49481VulnerabilityPublished 1 Jul 2025

CVE-2025-49481: ASR Falcon_Linux、Kestrel、Lapwing_Linux · Improper Resource Shutdown or Release

Affects ASR Falcon_Linux、Kestrel、Lapwing_LinuxSource CVE Database V5

Not known to be exploited · CVSS 5.4 Medium.

Data as of 26 Oct 2026, 06:15 UTC

CVSS 3.1 base score

5.4Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 20% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: None: There is no loss of integrity within 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 1 Jul 2025
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
ASR Falcon_Linux、Kestrel、Lapwing_Linux	Affected =0	Fixed in–

AI-suggested

European organizations should prioritize upgrading affected ASR router firmware to version v1536 or later once available to address this vulnerability. In the interim, network administrators should monitor router resource usage closely for signs of resource leaks, such as increasing memory or handle consumption over time. Implementing strict access controls to limit privileged access to router management interfaces can reduce exploitation risk. Network segmentation and traffic filtering can help contain potential exploitation attempts. Additionally, organizations should establish robust logging and alerting mechanisms to detect unusual router behavior indicative of resource exhaustion. Regular vulnerability scanning and penetration testing focused on network infrastructure can help identify exposure. Coordination with ASR support channels for timely patch information and applying vendor-recommended configurations to mitigate resource leaks is also advised.

Description

Improper Resource Shutdown or Release vulnerability in ASR180x 、ASR190x in router modules allows Resource Leak Exposure. This vulnerability is associated with program files router/phonebook/pbwork-queue.C. This issue affects Falcon_Linux、Kestrel、Lapwing_Linux: before v1536.

Impact

For European organizations, especially those relying on ASR routers running Falcon_Linux, Kestrel, or Lapwing_Linux, this vulnerability poses a risk of resource exhaustion that could degrade network performance or cause partial denial of service. While the confidentiality impact is limited, the availability impact could disrupt critical network services, affecting business operations, especially in sectors dependent on continuous network uptime such as finance, telecommunications, and government. The requirement of low privileges for exploitation means that insider threats or attackers who have gained limited access could leverage this vulnerability to impact network stability. Given the central role of routers in enterprise and service provider networks, exploitation could cascade to affect multiple connected systems. However, the absence of known exploits and the medium severity rating suggest that immediate widespread impact is unlikely but should not be ignored.

CWE-404Improper Resource Shutdown or Release (opens in a new tab)
Class weaknessLikelihood of exploit: Medium
The product does not release or incorrectly releases a resource before it is made available for re-use.
Requirements · Language Selection
Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
Implementation
It is good practice to be responsible for freeing all resources you allocate and to be consistent with how and where you free memory in a function. If you allocate memory that you intend to free upon completion of the function, you must be sure to free the memory at all exit points for that function including error…
Implementation
Memory should be allocated/freed using matching functions such as malloc/free, new/delete, and new[]/delete[].
Attack patterns
TCP Fragmentation (opens in a new tab)
UDP Fragmentation (opens in a new tab)
ICMP Fragmentation (opens in a new tab)
BlueSmacking (opens in a new tab)
Flooding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

asrmicro.com/en/goods/psirt?cid=40 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 1 Jul 2025, 11:39 UTC

WeaknessesCWE-404

Technical details

References

Community reviews

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