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Vulnerability details: VCID-qdxa-nfnh-zkfa
Vulnerability ID VCID-qdxa-nfnh-zkfa
Aliases CVE-2020-15254
GHSA-v5m7-53cv-f3hx
Summary In the crossbeam rust crate, the bounded channel incorrectly assumed that Vec::from_iter had allocated capacity that was the same as the number of iterator elements. Vec::from_iter does not actually guarantee that and may allocate extra memory. The destructor of the bounded channel reconstructs Vec from the raw pointer based on the incorrect assumptions - this is unsound and caused a deallocation with the incorrect capacity when Vec::from_iter had allocated different sizes than the number of iterator elements. The impact on Firefox is undetermined, but in another use case, the behavior was causing corruption of jemalloc structures.
Status Published
Exploitability 0.5
Weighted Severity 9.0
Risk 4.5
Affected and Fixed Packages Package Details
Weaknesses (2)
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-401 Missing Release of Memory after Effective Lifetime
System Score Found at
cvssv3 9.8 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-15254.json
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
epss 0.0051 https://api.first.org/data/v1/epss?cve=CVE-2020-15254
cvssv3.1_qr HIGH https://github.com/advisories/GHSA-v5m7-53cv-f3hx
cvssv3.1 8.1 https://github.com/crossbeam-rs/crossbeam
generic_textual HIGH https://github.com/crossbeam-rs/crossbeam
cvssv3.1 8.1 https://github.com/crossbeam-rs/crossbeam/issues/539
generic_textual HIGH https://github.com/crossbeam-rs/crossbeam/issues/539
cvssv3.1 8.1 https://github.com/crossbeam-rs/crossbeam/pull/533
generic_textual HIGH https://github.com/crossbeam-rs/crossbeam/pull/533
cvssv3.1 8.1 https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx
cvssv3.1_qr HIGH https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx
generic_textual HIGH https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx
cvssv3.1 8.1 https://github.com/RustSec/advisory-db/pull/425
generic_textual HIGH https://github.com/RustSec/advisory-db/pull/425
cvssv2 7.5 https://nvd.nist.gov/vuln/detail/CVE-2020-15254
cvssv3.1 8.1 https://nvd.nist.gov/vuln/detail/CVE-2020-15254
cvssv3.1 9.8 https://nvd.nist.gov/vuln/detail/CVE-2020-15254
generic_textual HIGH https://nvd.nist.gov/vuln/detail/CVE-2020-15254
cvssv3.1 8.1 https://rustsec.org/advisories/RUSTSEC-2020-0052.html
generic_textual HIGH https://rustsec.org/advisories/RUSTSEC-2020-0052.html
archlinux Critical https://security.archlinux.org/AVG-1256
generic_textual high https://www.mozilla.org/en-US/security/advisories/mfsa2020-45
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-15254.json
https://api.first.org/data/v1/epss?cve=CVE-2020-15254
https://github.com/crossbeam-rs/crossbeam
https://github.com/crossbeam-rs/crossbeam/issues/539
https://github.com/crossbeam-rs/crossbeam/pull/533
https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx
https://github.com/RustSec/advisory-db/pull/425
https://nvd.nist.gov/vuln/detail/CVE-2020-15254
https://rustsec.org/advisories/RUSTSEC-2020-0052.html
1963791 https://bugzilla.redhat.com/show_bug.cgi?id=1963791
ASA-202011-1 https://security.archlinux.org/ASA-202011-1
AVG-1256 https://security.archlinux.org/AVG-1256
cpe:2.3:a:crossbeam_project:crossbeam:*:*:*:*:*:*:*:* https://nvd.nist.gov/vuln/search/results?adv_search=true&isCpeNameSearch=true&query=cpe:2.3:a:crossbeam_project:crossbeam:*:*:*:*:*:*:*:*
GHSA-v5m7-53cv-f3hx https://github.com/advisories/GHSA-v5m7-53cv-f3hx
mfsa2020-45 https://www.mozilla.org/en-US/security/advisories/mfsa2020-45
USN-4599-1 https://usn.ubuntu.com/4599-1/
USN-4599-2 https://usn.ubuntu.com/4599-2/
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2020-15254.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/crossbeam-rs/crossbeam
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/crossbeam-rs/crossbeam/issues/539
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/crossbeam-rs/crossbeam/pull/533
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/crossbeam-rs/crossbeam/security/advisories/GHSA-v5m7-53cv-f3hx
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/RustSec/advisory-db/pull/425
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P Found at https://nvd.nist.gov/vuln/detail/CVE-2020-15254
Exploitability (E) Access Vector (AV) Access Complexity (AC) Authentication (Au) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

high

functional

unproven

proof_of_concept

not_defined

local

adjacent_network

network

high

medium

low

multiple

single

none

none

partial

complete

none

partial

complete

none

partial

complete
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2020-15254
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://nvd.nist.gov/vuln/detail/CVE-2020-15254
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://rustsec.org/advisories/RUSTSEC-2020-0052.html
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Exploit Prediction Scoring System (EPSS)
Percentile 0.65357
EPSS Score 0.0051
Published At July 30, 2025, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2025-07-31T08:09:44.480450+00:00 Mozilla Importer Import https://github.com/mozilla/foundation-security-advisories/blob/master/announce/2020/mfsa2020-45.yml 37.0.0