winrar: Improper Neutralization of Escape, Meta, or Control Sequences
CVE-2024-33899 is a high-severity improper neutralization of escape, meta, or control sequences vulnerability in winrar from Rarlab, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected winrar versions: 6.24 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 0.82% chance of exploitation within 30 days, higher than 58% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of winrar you run against the affected versions below, and install the vendor's latest release.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Rarlab | winrar | 6.24 and earlier | Not stated |
| Rarlab | unrar | 6.24 and earlier | Not stated |
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
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- 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:H/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
RARLAB WinRAR before 7.00, on Linux and UNIX platforms, allows attackers to spoof the screen output, or cause a denial of service, via ANSI escape sequences.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Escape, Meta, or Control Sequences
The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could be interpreted as escape, meta, or control character sequences when they are sent to a downstream component.
How developers prevent this class of flaw
- Developers should anticipate that escape, meta and control characters/sequences will be injected/removed/manipulated in the input vectors of their product. Use an appropriate combination of denylists and allowlists to ensure only valid, expected and appropriate input is processed by the system.
- While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
- Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
More Improper Neutralization of Escape, Meta, or Control Sequences vulnerabilities (CWE-150)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- rarlab.com/rarnew.htmRelease Notes
Technical write-ups (may include proof of concept)
- sdushantha.medium.com/ansi-escape-injection-vulnerability-in-winrar-a2cbfac4b983Exploit, Third Party Advisory
Other vulnerabilities in winrar
- 7.8 High severity
- 7.8 High severity
RARLAB WinRAR Path Traversal Exploited
- 7.8 High severity
- 7.8 High severity
RARLAB WinRAR Code Execution Exploited
- 7.1 High severity
Recent Improper Neutralization of Escape, Meta, or Control Sequences vulnerabilities
- 8.6 High severity
- 9.8 Critical severity
- 8.8 High severity
- 9.9 Critical severity
- 10.0 Critical severity
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