CVE-2025-5451VulnerabilityPublished 8 Jul 2025

CVE-2025-5451: Ivanti Connect Secure · Stack-based Buffer Overflow

Affects Ivanti Connect SecureSource CVE Database V5

Not known to be exploited · CVSS 4.9 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.9Medium

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

EPSS: 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
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 8 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

AI-suggested

European organizations should prioritize upgrading Ivanti Connect Secure to version 22.7R2.8 or later, and Ivanti Policy Secure to version 22.7R1.5 or later, as these versions contain fixes for the buffer overflow vulnerability. Until patching is possible, organizations should implement strict access controls to limit administrative access only to trusted personnel and monitor admin account activities for suspicious behavior. Employing multi-factor authentication (MFA) for admin accounts can reduce the risk of credential compromise. Network segmentation should be used to isolate management interfaces of Ivanti appliances from general network access, limiting exposure to potential attackers. Additionally, organizations should enable and review detailed logging and alerting on the Ivanti devices to detect anomalous admin activities that could indicate exploitation attempts. Regular vulnerability scanning and penetration testing focusing on remote access infrastructure can help identify residual risks. Finally, incident response plans should include procedures for rapid recovery from DoS conditions affecting remote access services to minimize operational impact.

Description

A stack-based buffer overflow in Ivanti Connect Secure before version 22.7R2.8 and Ivanti Policy Secure before version 22.7R1.5 allows a remote authenticated attacker with admin rights to trigger a denial of service.

Impact

For European organizations, the primary impact of CVE-2025-5451 is the potential disruption of remote access services provided by Ivanti Connect Secure and Policy Secure appliances. Since these products are commonly deployed to enable secure VPN connections for remote employees and partners, a successful exploitation could result in denial of service, preventing legitimate users from accessing critical internal resources. This can lead to operational downtime, reduced productivity, and potential delays in business processes reliant on remote connectivity. Although the vulnerability does not allow data theft or system compromise beyond DoS, the loss of availability in a remote access solution can have cascading effects, especially for organizations with distributed workforces or critical infrastructure requiring continuous remote management. Additionally, the requirement for administrative privileges limits the attack surface to insiders or compromised admin accounts, but insider threats or credential theft scenarios cannot be discounted. In sectors such as finance, healthcare, and government within Europe, where secure remote access is essential and regulated, such disruptions could also have compliance and reputational consequences.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
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…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

forums.ivanti.com/s/article/July-Security-Advisory-Ivanti-Connect-Secure-and-Ivanti-Policy-Secure-Multiple-CVEs (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 15 Jul 2025, 21:59 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

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