CVE-2025-5520VulnerabilityPublished 3 Jun 2025

CVE-2025-5520: Open5GS · Reachable Assertion

Affects Open5GSSource CVE Database V5

Mentioned vulnerabilities

CVE-2025-1893

Not known to be exploited · CVSS 6.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score

6.9Medium

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

EPSS: 0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: None
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: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
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: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: None: There is no loss of integrity within 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 3 Jun 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
GitHubopen5gs/open5gs`pkg:github/open5gs/open5gs`Other threats	Affected =2.7.0 =2.7.1 =2.7.2 =2.7.3	Fixed in–

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

AI-suggested

1. Immediate application of the official patch identified by commit 9f5d133657850e6167231527514ee1364d37a884 to all Open5GS deployments running affected versions (2.7.0 to 2.7.3). 2. Conduct thorough testing in staging environments before production deployment to ensure stability post-patch. 3. Implement network-level protections such as rate limiting and anomaly detection on interfaces exposing AMF/MME services to detect and block abnormal authentication traffic patterns that could trigger the assertion. 4. Employ strict access controls and network segmentation to limit exposure of the 5G core network components to untrusted networks. 5. Monitor system logs and alerts for signs of assertion failures or crashes related to authentication state processing. 6. Maintain up-to-date inventory of Open5GS versions in use and establish a patch management process for timely updates. 7. Engage with Open5GS community and security advisories to track any emerging exploits or related vulnerabilities. 8. Consider deploying redundancy and failover mechanisms for AMF/MME components to minimize service impact in case of crashes.

Description

A vulnerability was found in Open5GS up to 2.7.3. It has been classified as problematic. Affected is the function gmm_state_authentication/emm_state_authentication of the component AMF/MME. The manipulation leads to reachable assertion. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 9f5d133657850e6167231527514ee1364d37a884. It is recommended to apply a patch to fix this issue. This is a different issue than CVE-2025-1893.

Impact

For European organizations, especially mobile network operators and infrastructure providers deploying Open5GS as part of their 5G core network, this vulnerability could lead to service disruptions. The AMF/MME components are central to user authentication and mobility management; a crash or denial of service here can interrupt subscriber connectivity, degrade network performance, and impact critical communications services. This could affect enterprises relying on private 5G networks, public mobile operators, and IoT service providers. Disruptions in mobile network availability can have cascading effects on emergency services, financial transactions, and industrial operations that depend on continuous connectivity. Given the remote exploitability without authentication, attackers could target vulnerable networks from outside, increasing the threat surface. While no active exploitation is reported, the public disclosure raises the risk of future attacks. European telecom operators must consider the potential for service outages and reputational damage, as well as regulatory scrutiny under frameworks like the NIS Directive and GDPR if service disruptions impact data availability or privacy.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Jul 2025, 06:16 UTC

Technical details

References

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