install/index.php in WebCalendar before 1.2.5 allows remote attackers to execute arbitrary code via the form_single_user_login parameter.
- Published
- Jan 27, 2020
- Updated
- Jun 16, 2026
- EPSS
- 79.8% · 100th percentile
- CWE
- CWE-74
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Action score
63
This week
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- CVSS
- 39 / 40 · 9.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 24 / 30 · 79.8%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| webcalendar project | webcalendar | cpe:2.3:a:webcalendar_project:webcalendar |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- webcalendar project webcalendarbefore 1.2.5
Same product
webcalendar project: all recordsOther highest-scoring records for the same primary product.
- CVE-2012-1496Local file inclusion in WebCalendar before 1.2.5.36Monitor
- CVE-2012-5385install/index.php in Craig Knudsen WebCalendar before 1.2.5 allows remote attackers to modify settings.php and possibly execute arbitrary co31Monitor
- CVE-2024-22635WebCalendar v1.3.0 was discovered to contain a reflected cross-site scripting (XSS) vulnerability via the component /WebCalendarvqsmnseug2/e24Monitor
- CVE-2017-10840Cross-site scripting vulnerability in WebCalendar 1.2.7 and earlier allows an attacker to inject arbitrary web script or HTML via unspecifie24Monitor
- CVE-2023-0289Cross-site Scripting (XSS) - Stored in craigk5n/webcalendar21Monitor
- CVE-2013-1422webcalendar before 1.2.7 shows the reason for a failed login (e.g., "no such user").21Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
Weaponized
A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.
Evidence
- Metasploit module ×1
- Exploit-DB entry ×2
- Proof-of-concept repository on GitHub ×1
Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.
| Source | Kind | Date |
|---|---|---|
| Exploit-DB entry | webapps | 2012-04-29 |
| Exploit-DB entry | webapps | 2012-04-23 |
| Metasploit module | exploit/linux/http/webcalendar_settings_execWebCalendar 1.2.4 Pre-Auth Remote Code Injectionexploit | 2012-04-23 |
| Proof-of-concept repository on GitHub | stars:0 | 2023-06-08 |
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.
- First PoC-2835 d
- Metasploit-2835 d
- Published
- TodaySep 29, 2026+2437 d
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.
No commit or PR link among the references.
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).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- HTTP Request SplittingCAPEC-105likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Format String InjectionCAPEC-135likelihood: High · High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.