# What is CVE-2022-24903?

> CVE-2022-24903 is a high-severity flaw (CVSS 8.1) in Rsyslog, published on 6 May 2022. 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 3.9%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2022-24903

## At a glance

- **Verdict:** Plan it in. No sign of exploitation and a low forecast. Patch it in your normal update cycle.
- **Precursor Intelligence risk score:** 48 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 8.1 out of 10)
- **Known to be exploited:** No, not on the list of flaws known to be exploited today
- **Chance of use in the next 30 days:** 3.9% (latest exploit-likelihood forecast)
- **Published:** 6 May 2022
- **Record last updated:** 7 November 2023
- **Main product:** Rsyslog
- **Affected products:** 4

## What is CVE-2022-24903? 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 read data, change data and take it offline.

### The official description

Rsyslog is a rocket-fast system for log processing. Modules for TCP syslog reception have a potential heap buffer overflow when octet-counted framing is used. This can result in a segfault or some other malfunction. As of our understanding, this vulnerability can not be used for remote code execution. But there may still be a slight chance for experts to do that. The bug occurs when the octet count is read. While there is a check for the maximum number of octets, digits are written to a heap buffer even when the octet count is over the maximum, This can be used to overrun the memory buffer. However, once the sequence of digits stop, no additional characters can be added to the buffer. In our opinion, this makes remote exploits impossible or at least highly complex. Octet-counted framing is one of two potential framing modes. It is relatively uncommon, but enabled by default on receivers. Modules `imtcp`, `imptcp`, `imgssapi`, and `imhttp` are used for regular syslog message reception. It is best practice not to directly expose them to the public. When this practice is followed, the risk is considerably lower. Module `imdiag` is a diagnostics module primarily intended for testbench runs. We do not expect it to be present on any production installation. Octet-counted framing is not very common. Usually, it needs to be specifically enabled at senders. If users do not need it, they can turn it off for the most important modules. This will mitigate the vulnerability.

### What kind of flaw is it?

- CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
- CWE-1284: Improper Validation of Specified Quantity in Input

### How an attack on it works

- Where an attacker can be: Anywhere on the internet
- How hard it is to pull off: Hard: conditions must line up
- Login needed first: No login needed
- Does someone have to click: No, nobody has to do anything
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`

## Is CVE-2022-24903 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 3.9%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 3.9%, 3.9%, 3.9%, 3.9%, 3.9%, 3.9%, 3.9%.

### Timeline

- 6 May 2022: Published
- 7 November 2023: Record last updated
- 19 November 2025: Exploit likelihood jumped
- 22 November 2025: Exploit likelihood fell

### How Precursor Intelligence ranks it

CVE-2022-24903 scores **48 out of 100 (Medium)**, with the action "Plan remediation".

Every published flaw gets a risk score from 0 to 100, kept up to date as the evidence changes. Four things go into the score, from the one that counts most to the ones that count less:

- Evidence it is being exploited: biggest factor
- How severe it is: strong factor
- How widely exposed it is: smaller factor
- Threat activity around it: smaller factor

85 and above is Critical. Anything confirmed as exploited is always marked for an emergency patch, whatever its score. When this flaw matches software you track, it lands in your list with its score and the reasons behind it.

## Who is affected by CVE-2022-24903?

The published record lists 4 products. Versions are as published: "before 8.2204.1" means every version up to, but not including, 8.2204.1.

- [Rsyslog](https://www.precursorintelligence.com/product/rsyslog/rsyslog) by [Rsyslog](https://www.precursorintelligence.com/vendors/rsyslog) (Application): before 8.2204.1
- [Debian Linux](https://www.precursorintelligence.com/product/debian/debian_linux) by [Debian](https://www.precursorintelligence.com/vendors/debian) (Operating system): 9.0, 10.0, 11.0
- [Active Iq Unified Manager](https://www.precursorintelligence.com/product/netapp/active_iq_unified_manager) by [Netapp](https://www.precursorintelligence.com/vendors/netapp) (Application): version not specified
- [Fedora](https://www.precursorintelligence.com/product/fedoraproject/fedora) by [Fedoraproject](https://www.precursorintelligence.com/vendors/fedoraproject) (Operating system): 35

## How do I fix CVE-2022-24903?

1. **Check whether you run it.** Compare 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.
2. **Apply the vendor’s fix.** Install the update named in the vendor’s advisory. We’ve put the advisory first in the list.
3. **If you can’t patch today.** Follow any mitigation the vendor publishes, and limit who can reach the affected system from the internet until the update is in.
4. **Keep an eye on it.** Track 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

- [github.com](https://github.com/rsyslog/rsyslog/commit/f211042ecbb472f9d8beb4678a65d272b6f07705) (Patch, Third-party advisory)
- [github.com](https://github.com/rsyslog/rsyslog/security/advisories/GHSA-ggw7-xr6h-mmr8) (Third-party advisory)
- [lists.debian.org](https://lists.debian.org/debian-lts-announce/2022/05/msg00028.html) (Mailing list, Third-party advisory)
- [lists.fedoraproject.org](https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GMNNXLCU2UORRVSZO24HL4KMVPK5PHVW/)
- [security.netapp.com](https://security.netapp.com/advisory/ntap-20221111-0002/) (Third-party advisory)
- [debian.org](https://www.debian.org/security/2022/dsa-5150) (Third-party advisory)

## Questions

### What is CVE-2022-24903?

CVE-2022-24903 is a high-severity flaw in Rsyslog, published on 6 May 2022. It can be attacked from anywhere on the internet without logging in, and nobody has to click anything. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2022-24903?

It scores 8.1 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2022-24903 is 48 out of 100, which is Medium. Its action is "Plan remediation". No sign of exploitation and a low forecast. Patch it in your normal update cycle.

### Is CVE-2022-24903 being exploited?

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 3.9%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2022-24903 affect?

For Rsyslog: before 8.2204.1. The record lists 4 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2022-24903?

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.

## Does CVE-2022-24903 affect you?

Precursor Intelligence keeps checking for you:

- **Tell us what you run.** Pick your software from a list, or let us work it out from your website.
- **We match it to every flaw.** Over 400,000 published flaws, checked against your list.
- **Ranked by real-world risk.** Every flaw gets a 0 to 100 risk score, kept up to date, led by evidence criminals are using it.
- **Told as soon as we know.** An alert by email, in the app or by webhook to your own tools.

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