EGroupware Vulnerable to Local File Inclusion via file:// URI in Mail Compose
Summary
The function processes image URLs embedded in an HTML email body without validating or restricting URI schemes. The check
!str_starts_with($myUrl, 'http') evaluates to true for
file:// URIs, causing
file_get_contents($basedir . urldecode($myUrl)) to read arbitrary files from the server filesystem and embed them as inline MIME attachments in outgoing email.
str_starts_with('file:///etc/passwd', 'http') → false
!false → true
// api/src/Mail.php
foreach($images[2] as $i => $url)
{
//$isData = false;
$basedir = $data = '';
$needTempFile = true;
$attachmentData = ['name' => '', 'type' => '', 'file' => '', 'tmp_name' => ''];
try
{
// do not change urls for absolute images (thanks to corvuscorax)
if (!str_starts_with($url, 'data:'))
{
$attachmentData['name'] = basename($url); // need to resolve all sort of url
if (($directory = dirname($url)) == '.') $directory = '';
$ext = pathinfo($attachmentData['name'], PATHINFO_EXTENSION);
$attachmentData['type'] = MimeMagic::ext2mime($ext);
if ( strlen($directory) > 1 && !str_ends_with($directory, '/')) { $directory .= '/'; }
..
...
....
// processURL2InlineImages function
if ( $myUrl[0]!='/' && strlen($basedir) > 1 && !str_ends_with($basedir, '/')) { $basedir .= '/'; }
if ($needTempFile && empty($attachment) && !str_starts_with($myUrl, "http"))
{
try {
$data = file_get_contents($basedir.urldecode($myUrl));
}
catch (\Throwable $e) {
_egw_log_exception($e);
}
}
}
if (str_starts_with($url, 'data:'))
PoC
- Log in as any authenticated EGroupware user with mail access and open the mail compose window.
- Switch to HTML body mode and insert: `
.
- The server executes file_get_contents('file:///etc/passwd'), writes the content to a temp file, and attaches it as an inline MIME part.
Impact
An authenticated attacker can read arbitrary files accessible by the web server process, including /etc/passwd, application configuration files containing database credentials, private TLS keys, and environment files.
Remediation
Enforce a strict URI scheme allowlist before calling file_get_contents(). Replace the check !str_starts_with($myUrl, 'http')
with if (!preg_match('#^https?://#i', $myUrl)) { continue; }
to reject file://
, ftp://
, php://
, data://`, and any other non-HTTP scheme.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.the CNA's CVSS · CVSS v3.0 or v3.1
- EG Likelihood
- Unknown (no EPSS on record)Unknown, not low: FIRST has published no EPSS probability for this CVE.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).
A fix is available. Apply it within your standard update timelines.
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it