CVE-2025-40910 in Net::IP::LPM
Summary
by MITRE • 06/27/2025
Net::IP::LPM version 1.10 for Perl does not properly consider leading zero characters in IP CIDR address strings, which could allow attackers to bypass access control that is based on IP addresses.
Leading zeros are used to indicate octal numbers, which can confuse users who are intentionally using octal notation, as well as users who believe they are using decimal notation.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/27/2025
The vulnerability identified as CVE-2025-40910 affects the Net::IP::LPM Perl module version 1.10 and represents a significant security flaw in IP address handling mechanisms. This issue stems from the module's improper parsing of IP CIDR address strings that contain leading zero characters, which can be interpreted as octal notation by the parser. The vulnerability creates a potential bypass mechanism for access control systems that rely on IP address-based restrictions, as attackers can manipulate IP address representations to evade security measures. The flaw specifically impacts systems where IP-based access control is implemented, particularly in network security applications, firewalls, and authentication systems that depend on accurate IP address validation.
The technical root cause of this vulnerability lies in the module's failure to properly distinguish between octal and decimal representations of IP address components. When leading zeros are present in IP address octets, the parsing logic treats them as octal numbers rather than decimal values, which can result in incorrect IP address interpretation. For example, an IP address like 192.168.010.1 could be misinterpreted due to the leading zero in the third octet, potentially allowing an attacker to craft IP addresses that bypass intended access restrictions. This parsing inconsistency creates a scenario where legitimate security controls based on IP address matching may fail, as the system processes the malformed IP addresses differently than intended.
The operational impact of this vulnerability extends beyond simple access control bypasses and represents a broader concern for network security implementations. Systems relying on IP-based access control mechanisms, including web applications, network firewalls, and security appliances, may be vulnerable to attacks that exploit this parsing inconsistency. The vulnerability particularly affects environments where strict IP-based restrictions are enforced, such as administrative interfaces, API gateways, and network segmentation controls. Attackers could potentially leverage this flaw to gain unauthorized access to restricted resources by crafting IP addresses that appear valid but are actually processed differently due to the leading zero handling issue. This vulnerability aligns with CWE-704, which covers incorrect type conversion or parsing errors, and demonstrates how seemingly minor parsing inconsistencies can create significant security implications.
Organizations implementing security controls based on IP address validation must consider this vulnerability as a potential risk to their access control mechanisms. The flaw particularly impacts systems where IP address ranges are used for access control lists, firewall rules, or authentication restrictions. Mitigation strategies should focus on updating to patched versions of the Net::IP::LPM module or implementing additional validation layers that normalize IP address representations before processing. Security teams should also conduct thorough audits of all systems that rely on IP-based access controls to identify potential exposure to this vulnerability. The issue relates to ATT&CK technique T1078.002 which covers valid accounts and can be exploited through network access control bypasses, making it particularly concerning for environments with strict network segmentation policies. Additionally, implementing proper input validation and normalization of IP address representations can provide defense-in-depth measures against similar parsing vulnerabilities in other network security components.