CVE-2021-32810 | Data race in crossbeam-deque

crossbeam-deque is a package of work-stealing deques for building task schedulers when programming in Rust. In versions prior to 0.7.4 and 0.8.0, the result of the race condition is that one or more tasks in the worker queue can be popped twice instead of other tasks that are forgotten and never popped. If tasks are allocated on the heap, this can cause double free and a memory leak. If not, this still can cause a logical bug. Crates using `Stealer::steal`, `Stealer::steal_batch`, or `Stealer::steal_batch_and_pop` are affected by this issue. This has been fixed in crossbeam-deque 0.8.1 and 0.7.4.

Published: 2021-08-02 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-32810 is rated High Risk (65.5/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 1.08%). Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-32810

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 1.76% 1.08% -0.68%
2 2025-11-18 1.05% 1.76% +0.71%
3 2025-03-30 1.05%

Full EPSS history (17 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-32810

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 5.9 [email protected]
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
8.6 6.4 [email protected]

Weakness enumeration for CVE-2021-32810

GitHub Security Advisory for CVE-2021-32810

GHSA-pqqp-xmhj-wgcw · Severity: critical · Ecosystem: rust — crossbeam-deque Data Race before v0.7.4 and v0.8.1

OS Trackers for CVE-2021-32810

vendor priority summary link
alpine critical CVE-2021-32810: 4 source package rows (firefox, firefox-esr, librewolf, thunderbird); 24 state rows across 7 repos (3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 24, open 0. https://security.alpinelinux.org/vuln/CVE-2021-32810
debian unimportant CVE-2021-32810 unimportant priority: Debian including 4 source packages (firefox, firefox-esr, rust-crossbeam-deque, thunderbird), 16 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 15, open 1. https://security-tracker.debian.org/tracker/CVE-2021-32810
redhat medium https://access.redhat.com/security/cve/CVE-2021-32810
suse critical CVE-2021-32810 severity critical: SUSE including 59 source package names (MozillaFirefox-140.2.0-160000.1.2, MozillaFirefox-91.2.0-112.74.1, …), 278 product×package rows across 77 product lines (Container suse/kiosk/firefox-esr, HPE Helion OpenStack 8, … (77 product lines)): Fixed 278. https://www.suse.com/security/cve/CVE-2021-32810/
ubuntu medium CVE-2021-32810 medium priority: Ubuntu including 2 source packages (firefox, rust-crossbeam-deque), 30 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): released 13, not-affected 6, ignored 5, DNE 3, needs-triage 3. https://ubuntu.com/security/CVE-2021-32810

Affected software / configurations for CVE-2021-32810

Vendor Product Version Raw CPE
crossbeam_project crossbeam < 0.7.4 cpe:2.3:a:crossbeam_project:crossbeam:*:*:*:*:*:*:*:*
crossbeam_project crossbeam >= 0.8.0, < 0.8.1 cpe:2.3:a:crossbeam_project:crossbeam:*:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

References for CVE-2021-32810

URL Tags
https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-pqqp-xmhj-wgcw Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7EZILHZDRGDPOBQ4KTW3E5PPMKLHGH5N/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AWHNNBJCU4EHA2X5ZAMJMGLDUYS5FEPP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AYBSLIYFANZLCYWOGTIYZUM26TJRH7WU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CY5T3FCE4MUYSPKEWICLVJBBODGJ6SZE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EW5B2VTDVMJ6B3DA4VLMAMW2GGDCE2BK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LCIBFGBSL3JSVJQTNEDEIMZGZF23N2KE/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OCLMH7B7B2MF55ET4NQNPH7JWISFX4RT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RRPKBRXCRNGNMVFQPFD4LM3QKPEMBQQR/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TFUBWBYCPSSXTJGEAQ67CJUNQJBOCM26/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U3LSN3B43TJSFIOB3QLPBI3RCHRU5BLO/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VQZIEJQBV3S72BHD5GKJQF3NVYNRV5CF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WGB2H35CTZDHOV3VLC5BM6VFGURLLVRP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XFBZWCLG7AGLJO4A7K5IMJVPLSWZ5TJP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZQDIBB7VR3ER52FMSMNJPAWNDO5SITCE/
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