{"id":"CVE-2021-32635","aliases":["ALPINE-CVE-2021-32635","EUVD-2021-1270","GHSA-5mv9-q7fq-9394","MGASA-2022-0006","UBUNTU-CVE-2021-32635","openSUSE-SU-2024:11384-1"],"status":"published","title":"Action Commands (run/shell/exec) Against Library URIs Ignore Configured Remote Endpoint","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","severity":{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01415,"percentile":0.72968,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-20","CWE-923"],"published":"2021-05-28T20:20:12Z","modified":"2026-11-03T06:32:33Z","fixes":[{"ecosystem":"Go","package":"github.com/sylabs/singularity","fixed_in":["3.7.4"],"sources":["ghsa","osv"]},{"ecosystem":"Alpine:v3.19","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.20","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.21","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.22","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.23","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"singularity","fixed_in":["3.7.4-r0"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/sylabs/singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.7.2"},{"fixed":"3.7.4"}]}]},{"source":"osv","ecosystem":"Alpine:v3.19","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.20","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.21","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.22","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.7.4-r0"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/sylabs/singularity","ranges":[{"type":"SEMVER","events":[{"introduced":"3.7.2"},{"fixed":"3.7.4"}]}]},{"source":"osv","ecosystem":"Mageia:8","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.8.5-1.mga8"}]}],"bundled":3},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"singularity-container","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3.1-2","2.3.2-1","2.4.1-1","2.4.2-2","2.4.2-3","2.4.2-4","2.4.2-4ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"singularity-container","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.1+ds2-1","4.1.1+ds2-1build1","4.1.1+ds2-1ubuntu0.1","4.1.1+ds2-1ubuntu0.2","4.1.1+ds2-1ubuntu0.2+esm1","4.1.1+ds2-1ubuntu0.3","4.1.1+ds2-1ubuntu0.3+esm1","4.1.1+ds2-1ubuntu0.3+esm2"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"singularity-container","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.5+ds4-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"singularity-container","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.5+ds4-1"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"singularity","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.8.3-1.2"}]}],"bundled":12}],"products":[{"vendor":"sylabs","product":"singularity"}],"references":[{"url":"https://github.com/sylabs/singularity/security/advisories/GHSA-5mv9-q7fq-9394","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web","report"]},{"url":"https://github.com/sylabs/singularity/releases/tag/v3.7.4","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://security.gentoo.org/glsa/202107-50","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/hpcng/singularity/security/advisories/GHSA-jq42-hfch-42f3","tags":["web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-32635","tags":["advisory"]},{"url":"https://github.com/sylabs/singularity/commit/d52ae9d13979733c5e987a566fae59ed6f1bf796","tags":["web"]},{"url":"https://github.com/advisories/GHSA-5mv9-q7fq-9394"},{"url":"https://security.alpinelinux.org/vuln/CVE-2021-32635","tags":["advisory"]},{"url":"https://github.com/sylabs/singularity","tags":["package"]},{"url":"https://advisories.mageia.org/MGASA-2022-0006.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=29027","tags":["report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/BMX7XV7YNNNOVKKIOOPNENIXY64H4ZEY/","tags":["web"]},{"url":"https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/U5WJLLGD3LSUWRS73C4NPIWYTMST4QO5/","tags":["web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/D2IU6GJMCV5CQKUQZLHBP6EHSIZZXC3X/","tags":["web"]},{"url":"https://lists.opensuse.org/archives/list/security-announce@lists.opensuse.org/thread/L3AGIEOXZIUUEYYMWKJCJCQI7V235UTR/","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2021-32635","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-32635","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2018-12021","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2018-19295","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2019-11328","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2019-19724","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-13845","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-13846","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-13847","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-15229","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-25039","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2020-25040","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-29136","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2021-32635","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2021-32635","title":"Action Commands (run/shell/exec) Against Library URIs Ignore Configured Remote Endpoint","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T20:20:12Z","modified":"2024-08-03T23:25:31.038Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-923","CWE-20"],"updated_at":"2026-11-02T14:33:06.658806Z"}],"euvd":[{"id":"EUVD-2021-1270","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T20:20:12Z","modified":"2024-08-03T23:25:31Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"updated_at":"2026-11-03T03:24:36.41075Z"}],"ghsa":[{"id":"GHSA-5mv9-q7fq-9394","title":"Action Commands (run/shell/exec) Against Library URIs Ignore Configured Remote Endpoint","description":"### Impact\n\nDue to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint.\n\nAn attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container.\n\nOnly action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint.\n\n### Patches\n\nAll users should upgrade to Singularity 3.7.4 or later.\n\nA patch was applied at: https://github.com/sylabs/singularity/commit/d52ae9d13979733c5e987a566fae59ed6f1bf796\n\n### Workarounds\n\nUsers who only interact with the default remote endpoint are not affected.\n\nInstallations with an execution control list configured to restrict execution to containers signed with specific secure keys are not affected.\n\n### For more information\n\nGeneral questions about the impact of the advisory can be asked in the:\n\n- [SingularityCE Slack Channel](https://singularityce.slack.com)\n- [SingularityCE Mailing List](https://groups.google.com/g/singularity-ce)\n\nAny sensitive security concerns should be directed to: security@sylabs.io\n\nSee our Security Policy here: https://sylabs.io/security-policy","status":"published","published":"2021-06-01T21:21:01Z","modified":"2023-02-03T05:00:52Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:36:41.247728Z"}],"nvd":[{"id":"CVE-2021-32635","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T21:15:09.02Z","modified":"2026-06-17T03:53:19.233Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium","assessor":"primary"},{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-20","CWE-923"],"updated_at":"2026-11-02T14:06:53.987491Z"}],"osv":[{"id":"ALPINE-CVE-2021-32635","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T21:15:09.02Z","modified":"2026-11-03T06:32:33.557555844Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"updated_at":"2026-11-03T07:17:20.312441Z"},{"id":"CVE-2021-32635","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T21:15:09.02Z","modified":"2026-10-24T10:50:24.280791814Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T15:44:19.793849Z"},{"id":"GHSA-5mv9-q7fq-9394","title":"Action Commands (run/shell/exec) Against Library URIs Ignore Configured Remote Endpoint","description":"### Impact\n\nDue to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint.\n\nAn attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container.\n\nOnly action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint.\n\n### Patches\n\nAll users should upgrade to Singularity 3.7.4 or later.\n\nA patch was applied at: https://github.com/sylabs/singularity/commit/d52ae9d13979733c5e987a566fae59ed6f1bf796\n\n### Workarounds\n\nUsers who only interact with the default remote endpoint are not affected.\n\nInstallations with an execution control list configured to restrict execution to containers signed with specific secure keys are not affected.\n\n### For more information\n\nGeneral questions about the impact of the advisory can be asked in the:\n\n- [SingularityCE Slack Channel](https://singularityce.slack.com)\n- [SingularityCE Mailing List](https://groups.google.com/g/singularity-ce)\n\nAny sensitive security concerns should be directed to: security@sylabs.io\n\nSee our Security Policy here: https://sylabs.io/security-policy","status":"published","published":"2021-06-01T21:21:01Z","modified":"2026-07-08T06:28:19.961414839Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:46:38.553953Z"},{"id":"UBUNTU-CVE-2021-32635","description":"Singularity is an open source container platform. In verions 3.7.2 and 3.7.3, Dde to incorrect use of a default URL, `singularity` action commands (`run`/`shell`/`exec`) specifying a container using a `library://` URI will always attempt to retrieve the container from the default remote endpoint (`cloud.sylabs.io`) rather than the configured remote endpoint. An attacker may be able to push a malicious container to the default remote endpoint with a URI that is identical to the URI used by a victim with a non-default remote endpoint, thus executing the malicious container. Only action commands (`run`/`shell`/`exec`) against `library://` URIs are affected. Other commands such as `pull` / `push` respect the configured remote endpoint. The vulnerability is patched in Singularity version 3.7.4. Two possible workarounds exist: Users can only interact with the default remote endpoint, or an installation can have an execution control list configured to restrict execution to containers signed with specific secure keys.","status":"published","published":"2021-05-28T21:15:00Z","modified":"2026-05-20T16:04:58.584420791Z","cvss":[{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"},{"version":"3.1","score":6.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L","level":"medium"}],"updated_at":"2026-11-02T15:54:27.332852Z"},{"id":"MGASA-2022-0006","title":"Updated singularity packages fix security vulnerability","description":"A dependency used to extract docker/OCI image layers can be tricked into\nmodifying host files by creating a malicious layer that has a symlink with\nthe name \".\" (or \"/\"), when running as root. (CVE-2021-29136)\nDde to incorrect use of a default URL, `singularity` action commands\n(`run`/`shell`/`exec`) specifying a container using a `library://` URI\nwill always attempt to retrieve the container from the default remote\nendpoint (`cloud.sylabs.io`) rather than the configured remote endpoint.\nAn attacker may be able to push a malicious container to the default\nremote endpoint with a URI that is identical to the URI used by a victim\nwith a non-default remote endpoint, thus executing the malicious container.\nOnly action commands (`run`/`shell`/`exec`) against `library://` URIs are\naffected. Other commands such as `pull` / `push` respect the configured\nremote endpoint. (CVE-2021-32635)\nIf a Content-Type header changed between two pulls of the same digest, a\nclient may interpret the resulting content differently. (CVE-2021-41190)\n","status":"published","published":"2022-01-05T22:45:33Z","modified":"2026-04-16T04:41:44.323902955Z","updated_at":"2026-11-02T15:49:41.849028Z"},{"id":"openSUSE-SU-2024:11384-1","title":"singularity-3.8.3-1.2 on GA media","description":"These are all security issues fixed in the singularity-3.8.3-1.2 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2024-06-15T00:00:00Z","modified":"2026-02-04T02:36:28.928556Z","updated_at":"2026-11-02T16:58:35.195147Z"}]}}