If left unpatched, CVE-2023-38487 could lead to major system disruptions or data loss.
Status: Modified
Last updated: 🕗 21 Nov 2024, 08:13 UTC
Originally published on: 🕓 04 Aug 2023, 16:15 UTC
Time between publication and last update: 474 days
CVSS Release: version 3
security-advisories@github.com
Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:L
CVE-2023-38487: HedgeDoc is software for creating real-time collaborative markdown notes. Prior to version 1.9.9, the API of HedgeDoc 1 can be used to create notes with an alias matching the ID of existing notes. The affected existing note can then not be accessed anymore and is effectively hidden by the new one. When the freeURL feature is enabled (by setting the `allowFreeURL` config option or the `CMD_ALLOW_FREEURL` environment variable to `true`), any user with the appropriate permissions can create a note by making a POST request to the `/new/<ALIAS>` API endpoint. The `<ALIAS>` parameter can be set to the ID of an existing note. HedgeDoc did not verify whether the provided `<ALIAS>` value corresponds to a valid ID of an existing note and always allowed creation of the new note. When a visitor tried to access the existing note, HedgeDoc will first search for a note with a matching alias before it searches using the ID, therefore only the new note can be accessed. Depending on the permission settings of the HedgeDoc instance, the issue can be exploited only by logged-in users or by all (including non-logged-in) users. The exploit requires knowledge of the ID of the target note. Attackers could use this issue to present a manipulated copy of the original note to the user, e.g. by replacing the links with malicious ones. Attackers can also use this issue to prevent access to the original note, causing a denial of service. No data is lost, as the original content of the affected notes is still present in the database. This issue was fixed in version 1.9.9. As a workaround, disabling freeURL mode prevents the exploitation of this issue. The impact can be limited by restricting freeURL note creation to trusted, logged-in users by enabling `requireFreeURLAuthentication`/`CMD_REQUIRE_FREEURL_AUTHENTICATION`.
The exploitability of CVE-2023-38487 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).
CVE-2023-38487 presents a challenge to exploit due to its high attack complexity, but the absence of privilege requirements still makes it a viable target for skilled attackers. A thorough security review is advised.
A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.
Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.
Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.
Above is the CVSS Sub-score Breakdown for CVE-2023-38487, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.
Below is the Impact Analysis for CVE-2023-38487, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.
The EPSS score estimates the probability that this vulnerability will be exploited in the near future.
EPSS Score: 0.088% (probability of exploit)
EPSS Percentile: 40.16%
(lower percentile = lower relative risk)
This vulnerability is less risky than approximately 59.84% of others.
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