CVE-2021-27376
nb-connect invalidly assumes the memory layout of std::net::SocketAddr
An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.
- Record
CVE-2021-27376- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 7.5 High
AV:N/AC:L/Au:N/C:P/I:P/A:P - Weakness
- CWE-119
- Updated
- 2026-11-02
CVE ListNo score
An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.
- Record
CVE-2021-27376- Updated
- 2026-11-02
EUVDEUVD-2021-1871No score
An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.
- Record
EUVD-2021-1871- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-rm4w-6696-r77p
nb-connect invalidly assumes the memory layout of std::net::SocketAddr
The nb-connect crate has assumed std::net::SocketAddrV4 and std::net::SocketAddrV6 have the same memory layout as the system C representation sockaddr. It has simply casted the pointers to convert the socket addresses to the system representation. The standard library does not say anything about the memory layout, and this will cause invalid memory access if the standard library changes the implementation. No warnings or errors will be emitted once the change happens.
- Record
GHSA-rm4w-6696-r77p- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
OSVGHSA-rm4w-6696-r77p
nb-connect invalidly assumes the memory layout of std::net::SocketAddr
The nb-connect crate has assumed std::net::SocketAddrV4 and std::net::SocketAddrV6 have the same memory layout as the system C representation sockaddr. It has simply casted the pointers to convert the socket addresses to the system representation. The standard library does not say anything about the memory layout, and this will cause invalid memory access if the standard library changes the implementation. No warnings or errors will be emitted once the change happens.
- Record
GHSA-rm4w-6696-r77p- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-119
- Updated
- 2026-11-02
OSVRUSTSEC-2021-0021
`nb-connect` invalidly assumes the memory layout of std::net::SocketAddr
The nb-connect crate has assumed std::net::SocketAddrV4
and std::net::SocketAddrV6 have the same memory layout as the system C representation
sockaddr. It has simply casted the pointers to convert the socket addresses to the
system representation. The standard library does not say anything about the memory
layout, and this will cause invalid memory access if the standard library
changes the implementation. No warnings or errors will be emitted once the
change happens.
- Record
RUSTSEC-2021-0021- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
nb-connectcrates.io | before 1.0.3 | 1.0.3 |
nb-connectcrates.io | 0.0.0-0 up to 1.0.3 | 1.0.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27376 is a critical vulnerability (CVSS 9.8) in Nb-connect Project Nb-connect, published February 14, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.45%, the 73rd percentile. Fixed in nb-connect 1.0.3.