Twittodon: Deserialization of Untrusted Data
CVE-2025-63950 is a high-severity deserialization of untrusted data vulnerability in Twittodon from Tomaszdunia, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Twittodon versions: 2023-02-28 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Twittodon you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Tomaszdunia | Twittodon | 2023-02-28 and earlier | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CISA (ADP).
Official description
An insecure deserialization vulnerability exists in the download.php script of the to3k Twittodon application through commit b1c58a7d1dc664b38deb486ca290779621342c0b (2023-02-28). The 'obj' parameter receives base64-encoded data that is passed directly to the unserialize() function without validation. This allows a remote, unauthenticated attacker to inject arbitrary PHP objects, leading to a denial of service.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/solonbarroso/vulnerability-research/blob/main/advisories/Twittodon/CVE-2025-63950.mdExploit, Third Party Advisory
- github.com/solonbarroso/vulnerability-research/blob/main/advisories/Twittodon/CVE-pending-Deserialization.mdExploit, Third Party Advisory
Recent Deserialization of Untrusted Data vulnerabilities
- 9.1 Critical severity
- 7.5 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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