What is CVE-2023-28755?A medium-severity flaw in Uri, explained.
CVE-2023-28755 is a medium-severity flaw (CVSS 5.3) in Uri from Ruby-Lang, published on 31 March 2023. It is not on the list of flaws known to be exploited today. The latest forecast puts its chance of use in the next 30 days at 2.6%. If you run an affected version, plan in the vendor’s fix.
Published 31 March 2023. Record last updated 4 November 2025. We keep this page's data up to date.
What is CVE-2023-28755? In plain terms.
It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can slow it down.
A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters. It causes an increase in execution time for parsing strings to URI objects. The fixed versions are 0.12.1, 0.11.1, 0.10.2 and 0.10.0.1.
What kind of flaw is it?
- CWE-1333Inefficient Regular Expression Complexity
How an attack on it works
Read straight from its severity rating, translated out of the shorthand.
- Where an attacker can beAnywhere on the internet
- How hard it is to pull offEasy: no special conditions
- Login needed firstNo login needed
- Does someone have to clickNo, nobody has to do anything
- What an attacker getsCan slow it down
Severity vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Is CVE-2023-28755 being exploited? Not that we know of.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.6%. That can change at any time, which is why we keep watching.
Timeline
- Published
- Record last updated
CVE-2023-28755 scores 22. Action: Monitor.
We keep the score of every published flaw up to date as the evidence changes. Four things go into the score, and evidence that criminals are actually using it counts most. In order:
- Evidence it is being exploitedBiggest factor
- How severe it isStrong factor
- How widely exposed it isSmaller factor
- Threat activity around itSmaller factor
85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score.
When CVE-2023-28755 matches software you track, it lands in your list with its score and the reasons behind it.
See your own ranked list →Who is affected by CVE-2023-28755? 3 products.
The published record lists 3 products from 3 vendors. If you run one of these, check your version, then go to the fix below.
- Application
Uri
by Ruby-Lang
Affected versionsup to 0.10.00.10.10.11.00.12.0 - Operating system
Fedora
Affected versions363738 - Operating system
Debian Linux
by Debian
Affected versions10.0
How do I fix CVE-2023-28755? Four steps.
- Check whether you run itCompare your versions with the affected products above. Not sure what you run? Precursor Intelligence can work it out from your public website, or you can pick it from a list.
- Apply the vendor’s fixInstall the update named in the vendor’s advisory. We’ve put the advisory first in the list.
- If you can’t patch todayFollow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
- Keep an eye on itTrack the product and we tell you as soon as we spot this flaw on the list of exploited flaws, or a jump in its exploit likelihood.
References
15 links- Advisory for CVE-2023-28755 (opens in a new tab)ruby-lang.org · 2023
- ruby/uri release (opens in a new tab)github.com
- Msg00033 (opens in a new tab)debian.org · 2023
- 27LUWREIFTP3MQAW7QE4PJM4DPAQJWXF (opens in a new tab)fedoraproject.org
- FFZANOQA4RYX7XCB42OO3P24DQKWHEKA (opens in a new tab)fedoraproject.org
- G76GZG3RAGYF4P75YY7J7TGYAU7Z5E2T (opens in a new tab)fedoraproject.org
Does CVE-2023-28755 affect you? We'll keep checking.
Looking flaws up one at a time doesn't scale. Tell us what you run once, and we tell you which flaws matter to you, in what order, and keep watching for new ones.
- Tell us what you runPick your software from a list, or let us work it out from your website.
- We match it to every flawOver 400,000 published flaws, checked against your list.
- Ranked by real-world riskA 0 to 100 score, led by evidence criminals are using it.
- Told as soon as we knowAn alert by email, in the app or by webhook to your own tools.
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1 new flaw affects software Acme tracks
A ReDoS issue was discovered in the URI component through 0.12.0 in Ruby through 3.2.1. The URI parser mishandles invalid URLs that have specific characters....
- Matched to
- Uri on Acme's software list
- What to do
- Plan in the vendor’s update
Sent to the alert recipients Acme chose. Also in the app and to Acme's webhook.
CVE-2023-28755 is a medium-severity flaw in Uri from Ruby-Lang, published on 31 March 2023. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can slow it down.
It scores 5.3 out of 10 on the CVSS severity scale, which is medium. Our risk score for CVE-2023-28755 is 22 out of 100, which is Low. Its action is "Monitor". No sign of exploitation and a low forecast. Patch it in your normal update cycle.
It is not on the list of flaws known to be exploited today. The latest forecast puts the chance of it being used in the next 30 days at 2.6%. That can change at any time, which is why we keep watching.
For Uri from Ruby-Lang: up to 0.10.0, 0.10.1, 0.11.0, 0.12.0. The record lists 3 products in all, each with its versions, under "Who is affected" on this page.
Install the update the vendor names in its advisory, linked first under "How do I fix" on this page. If you can't patch today, follow the vendor's mitigation and limit who can reach the affected system from the internet.