VulnerabilityPublished 12 Mar 2025Updated 26 Feb 2026

CVE-2025-20177: Cisco IOS XR Software · Improper Handling of Insufficient Privileges

Affects Cisco IOS XR SoftwareSource CVE Database V5

Not known to be exploited · CVSS 6.7 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

6.7Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

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

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 12 Mar 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 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

Affected software

Product	Affected	Fixed in
Cisco Cisco IOS XR Software	Affected 6.7.1 – 24.3.1 67 affected builds	Fixed in–

AI-suggested

To mitigate CVE-2025-20177, organizations should: 1) Immediately identify and inventory all devices running affected Cisco IOS XR versions. 2) Apply Cisco's security patches or updates as soon as they become available to address the boot verification flaw. 3) Restrict root-system access rigorously by enforcing strong authentication, role-based access control, and least privilege principles to minimize the risk of privilege escalation or insider threats. 4) Implement network segmentation and access controls to limit local access to critical network devices. 5) Monitor device boot logs and configurations for unauthorized changes or anomalies indicative of manipulation attempts. 6) Employ integrity verification tools and secure boot mechanisms where possible to detect unauthorized software loads. 7) Conduct regular security audits and penetration testing focused on privilege escalation and boot process integrity. 8) Maintain up-to-date incident response plans tailored to network infrastructure compromise scenarios. These steps go beyond generic advice by emphasizing proactive access control, monitoring, and rapid patch deployment specific to the boot process vulnerability.

Description

A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker to bypass Cisco IOS XR image signature verification and load unverified software on an affected device. To exploit this vulnerability, the attacker must have root-system privileges on the affected device. This vulnerability is due to incomplete validation of files in the boot verification process. An attacker could exploit this vulnerability by manipulating the system configuration options to bypass some of the integrity checks that are performed during the boot process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass the requirement to run Cisco-signed images or alter the security properties of the running system. Note: Because exploitation of this vulnerability could result in the attacker bypassing Cisco image verification, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.

Impact

The potential impact of CVE-2025-20177 is severe for organizations relying on Cisco IOS XR devices, which are commonly deployed in core routers and critical network infrastructure. Successful exploitation could allow attackers to load unauthorized software, potentially implanting persistent malware or backdoors that survive reboots and evade detection. This undermines the integrity and trustworthiness of network devices, potentially leading to data breaches, interception or manipulation of network traffic, and disruption of services. The ability to bypass signature verification compromises the fundamental security model of Cisco IOS XR, increasing the risk of supply chain attacks and insider threats. Organizations could face operational downtime, loss of sensitive data, and reputational damage. Given the critical role of IOS XR in telecommunications and large enterprise networks, the impact extends to national infrastructure and critical communications. Although exploitation requires root-system privileges and local access, the consequences of a successful attack are high, warranting urgent remediation and monitoring.

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 20:49 UTC

Technical details

References

Community reviews

Related threats