blog: Unchecked Return Value
CVE-2022-23626 is a high-severity unchecked return value vulnerability in blog from M1k1o, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected blog versions: < 1.4. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 9.87% chance of exploitation within 30 days, which is in the top 4.36% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of blog you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
Version data comes from the organisation that assigned the CVE. 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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.5 | High | CNA (github.com) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 6.5 | Medium | NVD |
Official description
m1k1o/blog is a lightweight self-hosted facebook-styled PHP blog. Errors from functions `imagecreatefrom*` and `image*` have not been checked properly. Although PHP issued warnings and the upload function returned `false`, the original file (that could contain a malicious payload) was kept on the disk. Users are advised to upgrade as soon as possible. There are no known workarounds for this issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unchecked Return Value
The product does not check the return value from a method or function.
How developers prevent this class of flaw
- Check the results of all functions that return a value and verify that the value is expected.
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Ensure that you account for all possible return values from the function.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/m1k1o/blog/security/advisories/GHSA-wmqj-5v54-24x4Third Party Advisory
Patches and release notes
- github.com/m1k1o/blog/commit/6f5e59f1401c4a3cf2e518aa85b231ea14e8a2efThird Party Advisory
Technical write-ups (may include proof of concept)
- packetstormsecurity.com/files/167235/m1k1os-Blog-1.3-Remote-Code-Execution.htmlExploit, Third Party Advisory, VDB Entry
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