CVE-2023-33182: Nextcloud Contacts photos only sanitized if mime type is all lower case
Noroxi assessment
Priority: Monitor (action score 17/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.84% (FIRST EPSS); higher than 58% of all records.
- Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
- No fixed version is recorded, but the references include a patch (commit or PR) link.
- Severity is disputed: the assigning authority (CNA) scores it 0.0, NVD 4.3.
Low priority for now. See the fix and affected versions sections below.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Contacts app for Nextcloud easily syncs contacts from various devices with your Nextcloud and allows editing. The unsanitized SVG is converted to a JavaScript blob (in memory data) that the Avatar can't render. Due to this constellation the missing sanitization does not seem to be exploitable. It is recommended that the Contacts app is upgraded to 5.0.3 or 4.2.4
- Published
- May 30, 2023
- Updated
- Jun 17, 2026
- EPSS
- 0.8% · 58th percentile
- CWE
- CWE-20
Report tools
Action score
17
Monitor
Low priority for now.
- CVSS
- 17 / 40 · 4.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.8%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 4.3
- CNA · GitHub_M
- 0.0
- 4.3 point gap
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| nextcloud | contacts | cpe:2.3:a:nextcloud:contacts |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- nextcloud contacts4.1.0 and later · before 4.2.4
- nextcloud contacts5.0.0 and later · before 5.0.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
nextcloud security-advisories
- >= 4.1.0, < 4.2.4, >= 5.0.0, < 5.0.3affected
Same product
nextcloud: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-66554Nextcloud Contacts vulnerable to Stored XSS in contacts app via organisation and title field21Monitor
- CVE-2021-39221Nextcloud is an open-source, self-hosted productivity platform.21Monitor
- CVE-2020-8281A missing file type check in Nextcloud Contacts 3.3.0 allows a malicious user to upload malicious SVG files to perform cross-site scripting 21Monitor
Published before and after this one in the same product
- ← EarlierCVE-2018-3764Jul 5, 2018 · In Nextcloud Contacts before 2.1.2, a missing sanitization of search results for an autocomplete field could lead to a stored XSS requiring 19Monitor
- ← EarlierCVE-2020-8181Jul 10, 2020 · A missing file type check in Nextcloud Contacts 3.2.0 allowed a malicious user to upload any file as avatars.17Monitor
- ← EarlierCVE-2020-8280Jan 6, 2021 · A missing file type check in Nextcloud Contacts 3.4.0 allows a malicious user to upload SVG files as PNG files to perform cross-site scripti21Monitor
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
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
No history yet (it accumulates with the daily EPSS job).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
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
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- low · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- Low
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
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
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Show all references (2 more)Show less
Vendor advisories and official records. Exploit/PoC links are deliberately left out.