CVE-2021-29922

9.1 criticalEPSS 2.6%

Critical (9.1) in rust-lang rust. EPSS 2.6% chance of exploitation in the next 30 days.

library/std/src/net/parser.rs in Rust before 1.53.0 does not properly consider extraneous zero characters at the beginning of an IP address string, which (in some situations) allows attackers to bypass access control that is based on IP addresses, because of unexpected octal interpretation.

Severity

CVSS 3.1

9.1 critical

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

EPSS: 2.6% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)
Published: 2021-08-07
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

rust-lang:rust

References

https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudis
https://doc.rust-lang.org/beta/std/net/struct.Ipv4Addr.html
https://github.com/rust-lang/rust/issues/83648
https://github.com/rust-lang/rust/pull/83652
https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-015.md

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