CVE-2021-29922
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,…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
- EPSS
- 2.62% probability · 85th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- rust-lang/rust
- Source
- cve@mitre.org
EPSS 2.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudisThird Party Advisory
- https://doc.rust-lang.org/beta/std/net/struct.Ipv4Addr.htmlVendor Advisory
- https://github.com/rust-lang/rust/issues/83648Exploit, Issue Tracking, Patch, Third Party Advisory
- https://github.com/rust-lang/rust/pull/83652Patch, Third Party Advisory
- https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-015.mdExploit, Third Party Advisory
- https://security.gentoo.org/glsa/202210-09Third Party Advisory
- https://defcon.org/html/defcon-29/dc-29-speakers.html#kaoudisThird Party Advisory
- https://doc.rust-lang.org/beta/std/net/struct.Ipv4Addr.htmlVendor Advisory
- https://github.com/rust-lang/rust/issues/83648Exploit, Issue Tracking, Patch, Third Party Advisory
- https://github.com/rust-lang/rust/pull/83652Patch, Third Party Advisory
- https://github.com/sickcodes/security/blob/master/advisories/SICK-2021-015.mdExploit, Third Party Advisory
- https://security.gentoo.org/glsa/202210-09Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.