{"answers":{"affected":"It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-4456 exists.","fix":"Upgrade to a fixed version.","what":"CVE-2021-4456 is a medium-severity vulnerability in MRSAM Net::CIDR, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-4456 and fix it if it is affected.\n\nWhat it is: CVE-2021-4456 is a medium-severity vulnerability in MRSAM Net::CIDR, published on 27 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-4456 exists.\n\nAffected product: MRSAM Net::CIDR. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-4456/ (Markdown: https://insights.sbomify.com/CVE-2021-4456/index.md)","id":"CVE-2021-4456","markdown":"https://insights.sbomify.com/CVE-2021-4456/index.md","name":"CVE-2021-4456","record":{"aliases":["DEBIAN-CVE-2021-4456","GHSA-6xjh-63ff-92mc","UBUNTU-CVE-2021-4456","USN-8110-1","openSUSE-SU-2026:10756-1","openSUSE-SU-2026:20773-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Perl IP CIDR library","requires_auth":"none","summary":"Attackers can bypass IP-based access controls by exploiting leading zero mishandling in Net::CIDR Perl library functions.","user_interaction":"not_required","vuln_class":"security_feature_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"CPANSec","cpe":[{"product":"net\\","vendor":"mrsam"}],"cvss":{"score":6.5,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-704","name":"Incorrect Type Conversion or Cast"}],"description":"Net::CIDR versions before 0.24 for Perl mishandle leading zeros in IP CIDR addresses, which may have unspecified impact.\n\nThe functions `addr2cidr` and `cidrlookup` may return leading zeros in a CIDR string, which may in turn be parsed as octal numbers by subsequent users. In some cases an attacker may be able to leverage this to bypass access controls based on IP addresses.\n\nThe documentation advises validating untrusted CIDR strings with the `cidrvalidate` function. However, this mitigation is optional and not enforced by default. In practice, users may call `addr2cidr` or `cidrlookup` with untrusted input and without validation, incorrectly assuming that this is safe.","ecosystems":["openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"Net::CIDR versions before 0.24 for Perl mishandle leading zeros in IP CIDR addresses, which may have unspecified impact","id":"CVE-2021-4456","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"security_feature_bypass","year":"2021"},"n_packages":1,"n_references":3,"next":{"headline":"ZoomSounds \u003c 6.05 - Unauthenticated Arbitrary File Upload","id":"CVE-2021-4457"},"packages":[{"ecosystem":"openSUSE:Tumbleweed","fixed":["0.270.0-2.1"],"introduced":["0"],"last_affected":[],"package":"perl-Net-CIDR","purl":"pkg:rpm/opensuse/perl-Net-CIDR\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:10756-1"}],"prev":{"headline":"Wordpress Plugin Smart Product Review \u003c= 1.0.4 - Unauthenticated Arbitrary File Upload","id":"CVE-2021-4455"},"products":["Net::CIDR"],"published":"2026-02-27","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-02-27","vendors":["MRSAM"]},"summary":"Attackers can bypass IP-based access controls by exploiting leading zero mishandling in Net::CIDR Perl library functions.","url":"https://insights.sbomify.com/CVE-2021-4456/"}