CVE-2025-15251VulnerabilityPublished 30 Dec 2025

CVE-2025-15251: beecue FastBee · XML External Entity Reference

Affects beecue FastBeeSource CVE Database V5

Not known to be exploited · CVSS 6.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 4.0 base score

6.3Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 26% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X

Attack Vector: Network
Attack Complexity: High
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: Low
Vulnerable system integrity: Low
Vulnerable system availability: Low
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: High: The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques, for example, circumvention of address space randomization (ASLR) or data execution prevention (DEP) must be performed for the attack to be successful; Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system 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 Vulnerable System.
Vulnerable system 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 to the Vulnerable System.
Vulnerable system 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 Vulnerable System 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 Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Dec 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 2026-10-26.

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
GitHubbeecue/fastbee`pkg:github/beecue/fastbee`Other threats	Affected =2.0 =2.1	Fixed in–

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AI-suggested

European organizations should immediately audit their use of beecue FastBee versions 2.0 and 2.1, focusing on SIP Message Handler components. Network segmentation and restricting external access to SIP services can reduce exposure. Implement XML parsing hardening by disabling external entity processing where possible or using safer XML parsers that prevent XXE attacks. Monitor network traffic for anomalous XML payloads targeting SIP handlers. Engage with the vendor to obtain patches or updates as soon as they become available and plan prompt deployment. Employ intrusion detection systems (IDS) with signatures for XXE attempts and conduct regular security assessments of SIP infrastructure. Additionally, consider application-layer firewalls or API gateways that can sanitize or validate XML inputs before processing. Document and rehearse incident response plans for potential exploitation scenarios involving SIP service disruption or data leakage.

Description

A vulnerability was detected in beecue FastBee up to 2.1. Impacted is the function getRootElement of the file springboot/fastbee-server/sip-server/src/main/java/com/fastbee/sip/handler/req/ReqAbstractHandler.java of the component SIP Message Handler. The manipulation results in xml external entity reference. It is possible to launch the attack remotely. A high complexity level is associated with this attack. The exploitability is considered difficult. The project owner replied to the issue report: "Okay, we'll handle it as soon as possible."

Impact

For European organizations, particularly those in telecommunications or enterprises using SIP-based communication systems, this vulnerability poses a risk of sensitive information disclosure and service disruption. Although the impact on confidentiality, integrity, and availability is rated low, successful exploitation could expose internal configuration files or sensitive data, potentially aiding further attacks. The high complexity reduces the likelihood of widespread exploitation, but targeted attacks against critical infrastructure or high-value targets remain a concern. Disruption of SIP message handling could affect call setup and management, impacting business communications. Given the remote exploitability and lack of authentication requirements, attackers could attempt to leverage this vulnerability from outside the network perimeter if the affected services are exposed. The absence of known exploits in the wild currently limits immediate risk, but the vulnerability should be treated proactively to prevent future exploitation.

Summary

CVE-2025-15251 identifies an XML External Entity (XXE) vulnerability in the beecue FastBee product, versions 2.0 and 2.1. The flaw resides in the getRootElement function within the SIP Message Handler component, specifically in the file ReqAbstractHandler.java. This function improperly processes XML input, allowing an attacker to craft malicious XML payloads that include external entity references. When parsed, these references can cause the application to disclose internal files or resources, or potentially lead to denial of service by exhausting system resources. The vulnerability is remotely exploitable without requiring authentication or user interaction, but the attack complexity is high, making exploitation difficult. The CVSS 4.0 vector indicates network attack vector (AV:N), high attack complexity (AC:H), no privileges or user interaction required, and low impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). No public exploits have been reported, and the vendor has acknowledged the issue with plans to address it. The vulnerability affects SIP-based communication systems using FastBee, which may be integrated into telephony or VoIP infrastructures.

References

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