Security readout for executives and security teams
Plain-English summary
CVE-2020-26238 affects Java applications using cron-utils before 9.1.3 in a specific way. If untrusted cron expressions are validated through the @Cron annotation, attackers may inject Java EL expressions and reach remote code execution. Systems using cron-utils only for trusted expressions may not be exposed.
Executive priority
Prioritize remediation for internet-facing or multi-tenant systems that accept cron schedules from users. Lower urgency may be reasonable where cron-utils is absent, patched, or only processes trusted administrator-controlled expressions.
Technical view
cron-utils before 9.1.3 contains a template injection flaw classified as CWE-74. The disclosed affected path is @Cron annotation validation of untrusted cron expressions. The advisory states this can allow arbitrary Java EL expression injection and unauthenticated RCE. Version 9.1.3 contains the patch.
Likely exposure
Exposure is most likely in Java services, schedulers, workflow tools, or transitive dependencies using cron-utils versions before 9.1.3 and accepting cron expressions from users, tenants, APIs, configuration portals, or other untrusted sources.
Exploitation context
The source bundle does not show CISA KEV listing or confirmed active exploitation. Public sources describe the vulnerable condition and fix, but do not establish exploitation in the wild. Treat exploitable internet-facing cron validation as urgent because the claimed impact is code execution.
Researcher notes
The key exposure condition is narrow: vulnerable cron-utils version plus @Cron validation of untrusted cron expressions. Apache Hive mailing-list references show downstream dependency upgrade activity from 8.1.1 to 9.1.3, but the bundle does not prove every downstream consumer is exploitable.
Mitigation direction
- Upgrade cron-utils to version 9.1.3 or later.
- Prioritize applications validating untrusted cron expressions with @Cron.
- Check vendor guidance for products bundling cron-utils transitively.
- Restrict cron expression submission to trusted administrators where upgrade is pending.
- Rebuild and redeploy affected Java artifacts after dependency updates.
Validation and detection
- Search SBOMs, lockfiles, and build files for cron-utils below 9.1.3.
- Review code for @Cron annotation on user-controlled cron expressions.
- Inspect deployed artifacts for bundled or shaded vulnerable cron-utils versions.
- Confirm external cron inputs are validated after the dependency upgrade.
- Review dependency advisories for platforms that embed cron-utils.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-74: Exact CWE lookup
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Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2020-26238 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.9 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N1.55.8Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.9HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/jmrozanec/cron-utils/security/advisories/GHSA-pfj3-56hm-jwq5CVE reference · x_refsource_CONFIRM
- https://github.com/jmrozanec/cron-utils/issues/461CVE reference · x_refsource_MISC
- https://github.com/jmrozanec/cron-utils/commit/4cf373f7352f5d95f0bf6512af8af326b31c835eCVE reference · x_refsource_MISC
- [hive-issues] 20210316 [jira] [Assigned] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-dev] 20210316 [jira] [Created] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210316 [jira] [Work started] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-gitbox] 20210316 [GitHub] [hive] achennagiri opened a new pull request #2081: HIVE-24890: Upgrade the cron-utils library from 8.1.1 to 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210316 [jira] [Work logged] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210316 [jira] [Updated] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210317 [jira] [Commented] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210317 [jira] [Resolved] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-issues] 20210317 [jira] [Work logged] (HIVE-24890) Upgrade to cron-utils 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
- [hive-gitbox] 20210317 [GitHub] [hive] yongzhi merged pull request #2081: HIVE-24890: Upgrade the cron-utils library from 8.1.1 to 9.1.3 due to CVE-2020-26238CVE reference · mailing-list, x_refsource_MLIST
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.