Access-control bypass via decimal parsing of octal addresses
Published Mar 18, 2024 · Updated Aug 29, 2024
Access-control bypass in Net::IPv4Addr 0.10 for Perl allows remote attackers to evade IP-based restrictions with crafted addresses. The ipv4_network function treats a leading-zero octet such as 010 as decimal 10, while operating systems resolve it as octal 8. Exploitation requires a consuming application to trust that conflicting network classification for access control, granting access otherwise denied.
Summary
What happened
Access-control bypass in Net::IPv4Addr 0.10 for Perl allows remote attackers to evade IP-based restrictions with crafted addresses. The ipv4_network function treats a leading-zero octet such as 010 as decimal 10, while operating systems resolve it as octal 8. Exploitation requires a consuming application to trust that conflicting network classification for access control, granting access otherwise denied.
The record
- CVE
- CVE-2021-47155
- Published
- Mar 18, 2024
- Updated
- Aug 29, 2024
- Vendor
- The Perl Foundation
- Product
- Perl
- Classifications
- CWE-284
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 18, 2024CVE publishedPublication date reported by the CVE source.
- Aug 29, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.10
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Net::IPv4Addr leading-zero parsing demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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