CVE-2021-30465: runc before 1.0.0-rc95 allows a Container Filesystem Breakout via Directory Traversal.
Noroxi assessment
Priority: Monitor (action score 37/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 10.2% (FIRST EPSS); higher than 95.7% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
- Fixed version: cockpit-podman (AlmaLinux:8) 11-1.module_el8.5.0+108+00865455, 29-2.module_el8.6.0+2876+9ed4eae2, 11-1.module_el8.5.0+2635+e4386a39; conmon (AlmaLinux:8) 2:2.0.15-1.module_el8.5.0+2635+e4386a39, 2:2.0.26-3.module_el8.7.0+3406+a17c4180, 2:2.0.15-1.module_el8.5.0+108+00865455; container-selinux (AlmaLinux:8) 2:2.130.0-1.module_el8.5.0+2635+e4386a39, 2:2.130.0-1.module_el8.5.0+108+00865455.
- Mentioned 2 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).
Low priority for now. Upgrade to cockpit-podman (AlmaLinux:8) 11-1.module_el8.5.0+108+00865455, 29-2.module_el8.6.0+2876+9ed4eae2, 11-1.module_el8.5.0+2635+e4386a39; conmon (AlmaLinux:8) 2:2.0.15-1.module_el8.5.0+2635+e4386a39, 2:2.0.26-3.module_el8.7.0+3406+a17c4180, 2:2.0.15-1.module_el8.5.0+108+00865455; container-selinux (AlmaLinux:8) 2:2.130.0-1.module_el8.5.0+2635+e4386a39, 2:2.130.0-1.module_el8.5.0+108+00865455 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
runc before 1.0.0-rc95 allows a Container Filesystem Breakout via Directory Traversal. To exploit the vulnerability, an attacker must be able to create multiple containers with a fairly specific mount configuration. The problem occurs via a symlink-exchange attack that relies on a race condition.
- BDU:2021-03670
- GHSA-c3xm-pvg7-gh7r
- ALSA-2021:2291
- ALSA-2021:2370
- ALSA-2021:2371
- DLA-3369-1
- GO-2022-0914
- openSUSE-SU-2021:0878-1
- openSUSE-SU-2021:1404-1
- openSUSE-SU-2021:1954-1
- openSUSE-SU-2021:3506-1
- openSUSE-SU-2024:11358-1
- RHSA-2021:1562
- RHSA-2021:1566
- RHSA-2021:2057
- RHSA-2021:2144
- RHSA-2021:2145
- RHSA-2021:2150
- RHSA-2021:2291
- RHSA-2021:2292
- Published
- May 27, 2021
- Updated
- Jun 16, 2026
- EPSS
- 10.2% · 95th percentile
- CWE
- CWE-362
Report tools
Action score
37
Monitor
Low priority for now.
- CVSS
- 34 / 40 · 8.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 3 / 30 · 10.2%
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| linuxfoundation | runc | cpe:2.3:a:linuxfoundation:runc |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Using runc? Add it to your stack and be the first to know about CVEs like this one. (Docker)
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fedoraproject fedora33
- fedoraproject fedora34
- linuxfoundation runcup to 0.1.1 inclusive
- linuxfoundation runc1.0.0
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | cockpit-podman | before 11-1.module_el8.5.0+108+00865455 | 11-1.module_el8.5.0+108+00865455 |
| AlmaLinux:8 | cockpit-podman | before 29-2.module_el8.6.0+2876+9ed4eae2 | 29-2.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | cockpit-podman | before 11-1.module_el8.5.0+2635+e4386a39 | 11-1.module_el8.5.0+2635+e4386a39 |
| AlmaLinux:8 | conmon | before 2:2.0.15-1.module_el8.5.0+2635+e4386a39 | 2:2.0.15-1.module_el8.5.0+2635+e4386a39 |
| AlmaLinux:8 | conmon | before 2:2.0.26-3.module_el8.7.0+3406+a17c4180 | 2:2.0.26-3.module_el8.7.0+3406+a17c4180 |
| AlmaLinux:8 | conmon | before 2:2.0.15-1.module_el8.5.0+108+00865455 | 2:2.0.15-1.module_el8.5.0+108+00865455 |
| AlmaLinux:8 | conmon | before 2:2.0.26-1.module_el8.6.0+2876+9ed4eae2 | 2:2.0.26-1.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | container-selinux | before 2:2.130.0-1.module_el8.5.0+2635+e4386a39 | 2:2.130.0-1.module_el8.5.0+2635+e4386a39 |
| AlmaLinux:8 | container-selinux | before 2:2.130.0-1.module_el8.5.0+108+00865455 | 2:2.130.0-1.module_el8.5.0+108+00865455 |
| AlmaLinux:8 | containernetworking-plugins | before 0.9.1-1.module_el8.6.0+2876+9ed4eae2 | 0.9.1-1.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | containernetworking-plugins | before 0.8.3-4.module_el8.5.0+2635+e4386a39 | 0.8.3-4.module_el8.5.0+2635+e4386a39 |
| AlmaLinux:8 | containernetworking-plugins | before 0.8.3-4.module_el8.5.0+108+00865455 | 0.8.3-4.module_el8.5.0+108+00865455 |
| AlmaLinux:8 | containers-common | before 1:0.1.41-4.module_el8.5.0+108+00865455 | 1:0.1.41-4.module_el8.5.0+108+00865455 |
| AlmaLinux:8 | containers-common | before 1:0.1.41-4.module_el8.5.0+2635+e4386a39 | 1:0.1.41-4.module_el8.5.0+2635+e4386a39 |
| AlmaLinux:8 | crit | before 3.12-9.module_el8.5.0+119+9a9ec082 | 3.12-9.module_el8.5.0+119+9a9ec082 |
| AlmaLinux:8 | crit | before 3.15-1.module_el8.6.0+2876+9ed4eae2 | 3.15-1.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | crit | before 3.12-9.module_el8.4.0+2496+12421f43 | 3.12-9.module_el8.4.0+2496+12421f43 |
| AlmaLinux:8 | crit | before 3.12-9.module_el8.3.0+2044+12421f43 | 3.12-9.module_el8.3.0+2044+12421f43 |
| AlmaLinux:8 | criu | before 3.12-9.module_el8.3.0+2044+12421f43 | 3.12-9.module_el8.3.0+2044+12421f43 |
| AlmaLinux:8 | criu | before 3.12-9.module_el8.4.0+2496+12421f43 | 3.12-9.module_el8.4.0+2496+12421f43 |
| AlmaLinux:8 | criu | before 3.12-9.module_el8.5.0+119+9a9ec082 | 3.12-9.module_el8.5.0+119+9a9ec082 |
| AlmaLinux:8 | criu | before 3.15-1.module_el8.6.0+2876+9ed4eae2 | 3.15-1.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | fuse-overlayfs | before 1.4.0-2.module_el8.6.0+2876+9ed4eae2 | 1.4.0-2.module_el8.6.0+2876+9ed4eae2 |
| AlmaLinux:8 | fuse-overlayfs | before 0.7.8-1.module_el8.5.0+2635+e4386a39 | 0.7.8-1.module_el8.5.0+2635+e4386a39 |
+96
Same product
linuxfoundation: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-21626runc container breakout through process.cwd trickery and leaked fds40Plan
- CVE-2025-52565container escape due to /dev/console mount and related races33Monitor
- CVE-2023-28642AppArmor bypass with symlinked /proc in runc31Monitor
Published before and after this one in the same product
- ← EarlierCVE-2019-19921Feb 12, 2020 · runc through 1.0.0-rc9 has Incorrect Access Control leading to Escalation of Privileges, related to libcontainer/rootfs_linux.go.28Monitor
- Later →CVE-2021-43784Dec 6, 2021 · Overflow in netlink bytemsg length field allows attacker to override netlink-based container configuration21Monitor
- Later →CVE-2022-29162May 17, 2022 · Incorrect Default Permissions in runc31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| almalinux:cockpit-podman | 11-1.module_el8.5.0+108+00865455 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:conmon | 2:2.0.15-1.module_el8.5.0+108+00865455 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:container-selinux | 2:2.130.0-1.module_el8.5.0+2635+e4386a39 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:containernetworking-plugins | 0.8.3-4.module_el8.5.0+2635+e4386a39 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:containers-common | 1:0.1.41-4.module_el8.5.0+108+00865455 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:crit | 3.12-9.module_el8.3.0+2044+12421f43 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:criu | 3.12-9.module_el8.4.0+2496+12421f43 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:fuse-overlayfs | 0.7.8-1.module_el8.5.0+108+00865455 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python-podman-api | 1.2.0-0.2.gitd0a45fe.module_el8.5.0+2635+e4386a39 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:python3-criu | 3.12-9.module_el8.3.0+2044+12421f43 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:skopeo | 1:0.1.41-4.module_el8.5.0+2635+e4386a39 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:skopeo-tests | 1:0.1.41-4.module_el8.5.0+108+00865455 · AlmaLinux:8 | Package registry (OSV) |
| alpine:k3s | 1.21.1.1-r0 · Alpine:v3.15 | Package registry (OSV) |
| alpine:runc | 1.0.0_rc95-r0 · Alpine:v3.12 | Package registry (OSV) |
| debian:runc | 1.0.0~rc93+ds1-5 · Debian:12 | Package registry (OSV) |
| Go:github.com/opencontainers/runc | 1.0.0-rc95 | Package registry (OSV) |
| opensuse:containerd | 1.4.4-lp152.2.6.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:docker | 20.10.6_ce-lp152.2.12.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| opensuse:docker-kubic | 20.10.9_ce-156.1 · openSUSE:Leap 15.3 | Package registry (OSV) |
| opensuse:runc | 1.0.0~rc93-lp152.2.3.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| red hat:docker | 2:1.13.1-206.git7d71120.el7_9 · Red Hat:rhel_extras_other:7 | Package registry (OSV) |
| red hat:jenkins | 0:2.277.3.1620985335-1.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:openshift | 0:4.7.0-202105160013.p0.git.df9c838.el7 · Red Hat:openshift:4.7::el7 | Package registry (OSV) |
| red hat:openshift-hyperkube | 0:4.7.0-202105160013.p0.git.df9c838.el7 · Red Hat:openshift:4.7::el7 | Package registry (OSV) |
| red hat:openshift-kuryr | 0:4.7.0-202105140104.p0.git.8b61936.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:openshift-kuryr-cni | 0:4.7.0-202105140104.p0.git.8b61936.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:openshift-kuryr-common | 0:4.7.0-202105140104.p0.git.8b61936.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:openshift-kuryr-controller | 0:4.7.0-202105140104.p0.git.8b61936.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:python3-kuryr-kubernetes | 0:4.7.0-202105140104.p0.git.8b61936.el8 · Red Hat:openshift:4.7::el8 | Package registry (OSV) |
| red hat:runc | 0:1.0.0-96.rhaos4.8.gitcd80260.el7 · Red Hat:openshift:4.7::el7 | Package registry (OSV) |
+17
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-23-0309 · May 31, 2023(IBM Güvenlik Bildirimi)
- TR-21-0465 · Jun 10, 2021(RedHat Güvenlik Güncellemesi Yayınladı)
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (9 more)Show less
- bugzilla.opensuse.org/show_bug.cgi?id=1185405
- github.com/opencontainers/runc/commit/0ca91f44f1664da834bc61115a849b56d22f595f
- github.com/opencontainers/runc/releases
- github.com/opencontainers/runc/security/advisories/GHSA-c3xm-pvg7-gh7r
- lists.debian.org/debian-lts-announce/2023/03/msg00023.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/35ZW6NBZSBH5PWIT7JU4HXOXGFVDCOHH/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4HOARVIT47RULTTFWAU7XBG4WY6TDDHV/
- security.gentoo.org/glsa/202107-26
- security.netapp.com/advisory/ntap-20210708-0003/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.