CVE-2021-29499 | Predictable SIF UUID Identifiers

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SIF is an open source implementation of the Singularity Container Image Format. The `siftool new` command and func siftool.New() produce predictable UUID identifiers due to insecure randomness in the version of the `github.com/satori/go.uuid` module used as a dependency. A patch is available in version >= v1.2.3 of the module. Users are encouraged to upgrade. As a workaround, users passing CreateInfo struct should ensure the `ID` field is generated using a version of `github.com/satori/go.uuid` that is not vulnerable to this issue.

Published: 2021-05-07 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-29499 is rated High Exploit Risk (63.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.32%). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-29499

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-29499

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 0.25% 0.32% +0.07%
2 2025-03-29 0.32% 0.25% -0.07%
3 2025-03-17 0.32%

Full EPSS history (12 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29499

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
3.9 3.6 [email protected]
4.0 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
8.0 2.9 [email protected]

Weakness enumeration for CVE-2021-29499

GitHub Security Advisory for CVE-2021-29499

GHSA-4gh8-x3vv-phhg · Severity: high · Ecosystem: go — Predictable SIF UUID Identifiers in github.com/sylabs/sif

OS Trackers for CVE-2021-29499

vendor priority summary link
debian not yet assigned CVE-2021-29499 not yet assigned priority: Debian including 1 source packages (golang-github-sylabs-sif), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-29499
ubuntu medium CVE-2021-29499 medium priority: Ubuntu including 2 source packages (golang-github-sylabs-sif, singularity-container), 26 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 13, needs-triage 5, DNE 4, needed 4. https://ubuntu.com/security/CVE-2021-29499

Affected software / configurations for CVE-2021-29499

Vendor Product Version Raw CPE
sylabs singularity_image_format < 1.2.3 cpe:2.3:a:sylabs:singularity_image_format:*:*:*:*:*:*:*:*

References for CVE-2021-29499

cvelogic Threat Intelligence