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Fencer Intel
critical 9.8

CVE-2021-31162 json

In the standard library in Rust before 1.52.0, a double free can occur in the Vec::from_iter function if freeing the element panics.

published 5y ago modified 4mo ago also EUVD-2021-18076

cvss
9.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

In the standard library in Rust before 1.52.0, a double free can occur in the Vec::from_iter function if freeing the element panics.

Patch / fix

  • rust-lang rust 1.52.0
  • rustc Debian 14, Debian 13, Debian 12 1.53.0+dfsg1-1

debian advisories DEBIAN-CVE-2021-31162

  • rustc Ubuntu 20.04 LTS 1.53.0+dfsg1+llvm-4ubuntu1~20.04.1
  • rustc Ubuntu 22.04 LTS 1.53.0+dfsg1+llvm-4ubuntu1

ubuntu advisories UBUNTU-CVE-2021-31162

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rls RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • rust RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • cargo RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • clippy RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • rustfmt RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • rust-gdb RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • rust-src RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9
  • rust-lldb RHEL 8 1.52.1-1.module+el8.4.0+11282+0729bac9

red hat advisories RHSA-2021:3063RHSA-2021:3042

  • rust Rocky Linux 8 1.52.1-1.module+el8.4.0+641+ca238f88
  • rust-toolset Rocky Linux 8 1.52.1-1.module+el8.4.0+641+ca238f88

rocky linux advisories RLSA-2021:3063

  • rust Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 1.51.0-r2
  • chromium-rust Alpine 3.24 1.51.0-r2

alpine advisories ALPINE-CVE-2021-31162

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rust Arch Linux 1:1.52.0-1

arch linux advisories AVG-1801

Is CVE-2021-31162 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-31162 updated cvss 9.8

rust: double free in Vec::from_iter function if freeing the element panics

  • Red Hat Developer Tools for Red Hat Enterprise Linux Server (v. 7) rust-toolset-1.52 1.52.1-1.el7_9, rust-toolset-1.52-rls 1.52.1-2.el7_9, rust-toolset-1.52-rust 1.52.1-2.el7_9, rust-toolset-1.52-build 1.52.1-1.el7_9, rust-toolset-1.52-cargo 1.52.1-2.el7_9, rust-toolset-1.52-clippy 1.52.1-2.el7_9, +7 more
    fixed: vendor fix RHSA-2021:3042
  • Red Hat Enterprise Linux AppStream (v. 8) rls 1.52.1-1.module+el8.4.0+11282+0729bac9, rust 1.52.1-1.module+el8.4.0+11282+0729bac9, cargo 1.52.1-1.module+el8.4.0+11282+0729bac9, clippy 1.52.1-1.module+el8.4.0+11282+0729bac9, rustfmt 1.52.1-1.module+el8.4.0+11282+0729bac9, rust-gdb 1.52.1-1.module+el8.4.0+11282+0729bac9, +5 more
    fixed: vendor fix RHSA-2021:3063
  • Red Hat Enterprise Linux 9 rust, cargo, clippy, rustfmt, rust-gdb, rust-src, +8 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.89% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/rust-lang/rust/issues/83618 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 7.5 AV:N/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.