CVE-2024-42010VulnerabilityPublished 5 Aug 2024Updated 12 Aug 2024

CVE-2024-42010: roundcubemail · n/a

Affects roundcubemailSource CVE Database V5

Not known to be exploited · 66% EPSS · CVSS 7.5 High.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 66.6% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 5 Aug 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubroundcube/roundcubemail`pkg:github/roundcube/roundcubemail`Other threats	Affected <=1.5.7 >=1.6.0 <=1.6.7	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

To mitigate CVE-2024-42010, organizations should first verify if their Roundcube installations use versions up to 1.5.7 or 1.6.x through 1.6.7 with the mod_css_styles plugin enabled. Immediate steps include disabling the mod_css_styles plugin if feasible, as this will prevent CSS processing that leads to the vulnerability. If disabling is not possible, organizations should monitor for updates or patches from the Roundcube development team and apply them promptly once available. In the interim, implement email filtering rules to detect and quarantine suspicious emails containing unusual CSS or style elements. Employ Content Security Policy (CSP) headers on the webmail server to restrict CSS execution contexts and reduce the risk of CSS-based attacks. Additionally, educate users about the risks of opening emails from unknown or untrusted sources. Network-level protections such as intrusion detection systems (IDS) can be tuned to detect anomalous email content patterns. Finally, conduct regular security assessments of webmail infrastructure to identify and remediate similar input validation weaknesses.

Description

mod_css_styles in Roundcube through 1.5.7 and 1.6.x through 1.6.7 insufficiently filters Cascading Style Sheets (CSS) token sequences in rendered e-mail messages, allowing a remote attacker to obtain sensitive information.

Impact

The primary impact of CVE-2024-42010 is unauthorized disclosure of sensitive information from users' email accounts accessed via Roundcube webmail. Attackers can remotely exploit this vulnerability by sending specially crafted emails containing malicious CSS, which when rendered by the vulnerable Roundcube instance, leaks confidential data. This can lead to exposure of personal information, internal communications, or credentials stored or accessible through the webmail interface. Since no authentication or user interaction is required, attackers can target any user with an email address on the affected system. Organizations relying on Roundcube for email services risk data breaches that could damage reputation, violate privacy regulations, and lead to further attacks leveraging the disclosed information. The vulnerability does not allow modification or destruction of data, nor does it cause denial of service, but the confidentiality breach alone is significant. The absence of known exploits in the wild currently limits immediate widespread impact, but the potential for targeted attacks against high-value organizations is substantial.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Feb 2026, 07:15 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

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