CVE-2020-35508

A flaw possibility of race condition and incorrect initialization of the process id was found in the Linux kernel child/parent process identification handling while filtering signal handlers. A local attacker is able to abuse this flaw to bypass checks to send any signal to a privileged process.

Published: 2021-03-26 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2020-35508 is rated Low Risk (22.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2020-35508

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 2025-03-30 0.17% 0.05% -0.11%
2 2025-03-29 0.05% 0.17% +0.11%
3 2025-03-17 0.05%

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-35508

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
1.0 3.4 [email protected]
4.4 2.0 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
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.
3.4 6.4 [email protected]

Weakness enumeration for CVE-2020-35508

OS Trackers for CVE-2020-35508

vendor priority summary link
debian not yet assigned CVE-2020-35508 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-35508
redhat medium https://access.redhat.com/security/cve/CVE-2020-35508
suse medium CVE-2020-35508 severity moderate: SUSE including 34 source package names (bpftool-4.18.0-305.el8, kernel-4.18.0-305.el8, …), 266 product×package rows across 55 product lines (HPE Helion OpenStack 8, SUSE CaaS Platform 4.0, … (55 product lines)): Known Not Affected 246, Fixed 20. https://www.suse.com/security/cve/CVE-2020-35508/
ubuntu low CVE-2020-35508 low priority: Ubuntu including 169 source packages (linux, linux-allwinner, …), 2181 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1696, not-affected 235, released 211, ignored 39. https://ubuntu.com/security/CVE-2020-35508

Affected software / configurations for CVE-2020-35508

Vendor Product Version Raw CPE
linux linux_kernel < 5.12 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 5.12 cpe:2.3:o:linux:linux_kernel:5.12:-:*:*:*:*:*:*
linux linux_kernel 5.12 cpe:2.3:o:linux:linux_kernel:5.12:rc1:*:*:*:*:*:*
linux linux_kernel 5.12 cpe:2.3:o:linux:linux_kernel:5.12:rc2:*:*:*:*:*:*
linux linux_kernel 5.12 cpe:2.3:o:linux:linux_kernel:5.12:rc3:*:*:*:*:*:*
linux linux_kernel 5.12 cpe:2.3:o:linux:linux_kernel:5.12:rc4:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
netapp a700s_firmware cpe:2.3:o:netapp:a700s_firmware:-:*:*:*:*:*:*:*
netapp brocade_fabric_operating_system_firmware cpe:2.3:o:netapp:brocade_fabric_operating_system_firmware:-:*:*:*:*:*:*:*
netapp fas8300_firmware cpe:2.3:o:netapp:fas8300_firmware:-:*:*:*:*:*:*:*
netapp fas8700_firmware cpe:2.3:o:netapp:fas8700_firmware:-:*:*:*:*:*:*:*
netapp aff_a400_firmware cpe:2.3:o:netapp:aff_a400_firmware:-:*:*:*:*:*:*:*
netapp h300s_firmware cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:*
netapp h500s_firmware cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:*
netapp h700s_firmware cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:*
netapp h300e_firmware cpe:2.3:o:netapp:h300e_firmware:-:*:*:*:*:*:*:*
netapp h500e_firmware cpe:2.3:o:netapp:h500e_firmware:-:*:*:*:*:*:*:*
netapp h700e_firmware cpe:2.3:o:netapp:h700e_firmware:-:*:*:*:*:*:*:*
netapp h410s_firmware cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:*
netapp h410c_firmware cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:*
netapp h610c_firmware cpe:2.3:o:netapp:h610c_firmware:-:*:*:*:*:*:*:*
netapp h610s_firmware cpe:2.3:o:netapp:h610s_firmware:-:*:*:*:*:*:*:*
netapp h615c_firmware cpe:2.3:o:netapp:h615c_firmware:-:*:*:*:*:*:*:*

References for CVE-2020-35508

cvelogic Threat Intelligence