# What is CVE-2018-0777?

> CVE-2018-0777 is a high-severity flaw (CVSS 7.5) in Edge from Microsoft, published on 4 January 2018. 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 78%. If you run an affected version, plan in the vendor’s fix.

Canonical page: https://www.precursorintelligence.com/what-is/cve-2018-0777

## At a glance

- **Verdict:** Fix this soon. Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.
- **Precursor Intelligence risk score:** 60 out of 100 (Medium); action: Plan remediation. Kept up to date as the evidence changes.
- **Severity:** High (CVSS 7.5 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:** 78% (latest exploit-likelihood forecast)
- **Published:** 4 January 2018
- **Record last updated:** 24 August 2020
- **Main product:** Edge from Microsoft
- **Affected products:** 4

## What is CVE-2018-0777? In plain terms

It can be attacked from anywhere on the internet without logging in, but a person has to take an action first. If it works, the attacker can read data, change data and take it offline.

### The official description

Microsoft Edge in Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows an attacker to execute arbitrary code in the context of the current user, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2018-0758, CVE-2018-0762, CVE-2018-0768, CVE-2018-0769, CVE-2018-0770, CVE-2018-0772, CVE-2018-0773, CVE-2018-0774, CVE-2018-0775, CVE-2018-0776, CVE-2018-0778, and CVE-2018-0781.

### What kind of flaw is it?

- CWE-787: Out-of-bounds Write

### 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: Yes, a person has to take an action
- What an attacker gets: Can read data, change data and take it offline

Severity vector: `CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`

## Is CVE-2018-0777 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 78%. That can change at any time, which is why we keep watching.

Exploit likelihood over the last 7 days: 78%, 78%, 78%, 78%, 78%, 78%, 78%.

### Timeline

- 4 January 2018: Published
- 24 August 2020: Record last updated

### How Precursor Intelligence ranks it

CVE-2018-0777 scores **60 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-2018-0777?

The published record lists 4 products. Versions are as published: "before 1.7.6" means every version up to, but not including, 1.7.6.

- [Edge](https://www.precursorintelligence.com/product/microsoft/edge) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Application): version not specified
- [Windows 10](https://www.precursorintelligence.com/product/microsoft/windows_10) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): 1511, 1607, 1703, 1709
- [Chakracore](https://www.precursorintelligence.com/product/microsoft/chakracore) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Application): before 1.7.6
- [Windows Server 2016](https://www.precursorintelligence.com/product/microsoft/windows_server_2016) by [Microsoft](https://www.precursorintelligence.com/vendors/microsoft) (Operating system): version not specified

## How do I fix CVE-2018-0777?

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

- [portal.msrc.microsoft.com](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0777) (Patch, Vendor advisory)
- [securityfocus.com](http://www.securityfocus.com/bid/102402) (Third-party advisory, Vulnerability database)
- [securitytracker.com](http://www.securitytracker.com/id/1040100) (Third-party advisory, Vulnerability database)
- [exploit-db.com](https://www.exploit-db.com/exploits/43718/) (Exploit, Third-party advisory, Vulnerability database)

## Questions

### What is CVE-2018-0777?

CVE-2018-0777 is a high-severity flaw in Edge from Microsoft, published on 4 January 2018. It can be attacked from anywhere on the internet without logging in, but a person has to take an action first. If it works, the attacker can read data, change data and take it offline.

### How serious is CVE-2018-0777?

It scores 7.5 out of 10 on the CVSS severity scale, which is high. Our risk score for CVE-2018-0777 is 60 out of 100, which is Medium. Its action is "Plan remediation". Not confirmed as exploited yet, but serious or likely enough that it should not wait for a quiet month.

### Is CVE-2018-0777 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 78%. That can change at any time, which is why we keep watching.

### Which versions does CVE-2018-0777 affect?

For Edge from Microsoft: version not specified. The record lists 4 products in all, each with its versions, under "Who is affected" on this page.

### How do I fix CVE-2018-0777?

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-2018-0777 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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