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CVE-2026-18664

Wrong interpretation of ACL ranges PUBLISHED

Description (CNA)

When ranges are used for access control (i.e. of the form 1.2.3.4-1.2.3.25), because NSD wrongly compares the IP address with the range on little endian systems, IPs that were meant to be allowed may be denied, and, IPs that were meant to be denied access could be allowed. An IPv4 address is compared with IPv4 ranges as unsigned 32 bit numbers directly with the endianness of the host, but the values to compare are in network byte order (big-endian). With IPv6 addresses the comparison is done in 4 times a unsigned 32 bit number comparison, again with the endianness of the host where all values are actually in network bye order.

Affected (CNA)

Vendor / productVersions
NLnet Labs / NSDaffected 3.0.0 before 4.15.1

CWE

CWE-284, CWE-697

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.