How severe is CVE-2021-3155?

CVE-2021-3155 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-3155 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3155?

CVE-2021-3155 primarily affects Canonical Snapd. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3155?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-3155 published?

CVE-2021-3155 was published on 2022-02-17 and last updated on 2026-06-17.

CVE-2021-3155

CVE-2021-3155 is a low-severity vulnerability in Canonical Snapd with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-276.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
CVSS v2: 2.1
EPSS exploit prediction: 0% (17th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-276
Affected product: Canonical Snapd
Published: 2022-02-17
Last modified: 2026-06-17

Description

snapd 2.54.2 and earlier created ~/snap directories in user home directories without specifying owner-only permissions. This could allow a local attacker to read information that should have been private. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

Frequently asked questions

What is CVE-2021-3155?: snapd 2.54.2 and earlier created ~/snap directories in user home directories without specifying owner-only permissions. This could allow a local attacker to read information that should have been private. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1
How severe is CVE-2021-3155?: CVE-2021-3155 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-3155 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3155?: CVE-2021-3155 primarily affects Canonical Snapd. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3155?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3155 published?: CVE-2021-3155 was published on 2022-02-17 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:canonical:snapd:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:21.10:*:*:*:*:*:*:*

More vulnerabilities in Canonical Snapd

CVE-2023-1523 — Critical (CVSS 10.0): Using the TIOCLINUX ioctl request, a malicious snap could inject contents into the input of the controlling terminal…
CVE-2019-7304 — Critical (CVSS 9.8): Canonical snapd before version 2.37.1 incorrectly performed socket owner validation, allowing an attacker to run…
CVE-2020-27352 — Critical (CVSS 9.3): When generating the systemd service units for the docker snap (and other similar snaps), snapd does not specify…
CVE-2021-4120 — High (CVSS 8.2): snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the…
CVE-2024-5138 — High (CVSS 8.1): The snapctl component within snapd allows a confined snap to interact with the snapd daemon to take certain privileged…
CVE-2022-3328 — High (CVSS 7.8): Race condition in snap-confine's must_mkdir_and_open_with_perms()

All CVEs affecting Canonical Snapd →

Other CWE-276 (Incorrect Default Permissions) vulnerabilities

CVE-2022-42150 — Critical (CVSS 10.0): TinyLab linux-lab v1.1-rc1 and cloud-labv0.8-rc2, v1.1-rc1 are vulnerable to insecure permissions. The default…
CVE-2020-29492 — Critical (CVSS 10.0): Dell Wyse ThinOS 8.6 and prior versions contain an insecure default configuration vulnerability. A remote…
CVE-2020-29491 — Critical (CVSS 10.0): Dell Wyse ThinOS 8.6 and prior versions contain an insecure default configuration vulnerability. A remote…
CVE-2025-40585 — Critical (CVSS 9.9): A vulnerability has been identified in Energy Services (All versions with G5DFR). Affected solutions using G5DFR…
CVE-2019-19896 — Critical (CVSS 9.9): In IXP EasyInstall 6.2.13723, there is Remote Code Execution via weak permissions on the Engine Service share. The…
CVE-2020-37129 — Critical (CVSS 9.8): Memu Play 7.1.3 contains an insecure folder permissions vulnerability that allows low-privileged users to modify the…

Browse all CWE-276 (Incorrect Default Permissions) vulnerabilities →