Improper Restriction of XML External Entity Reference vulnerability in Apache Camel Saxon component.
This issue affects Apache Camel: from 4.0.0 before 4.18.5, from 4.19.0 before 4.22.2.
XQueryBuilder in camel-saxon, which evaluates expressions for the xquery language and the xquery component, built its default Saxon Configuration with parse options that set only a whitespace stripping rule, leaving the XML parser at its defaults, under which a DOCTYPE declaration is accepted and external entities are resolved. A message body of type String or byte[], or any body read as an InputStream, is first turned into a javax.xml.transform.Source by Camel's own XML type converters, which configure the parser against external entities, so those bodies were not affected. A body that was already a Source, however, was handed to Saxon unchanged, and when that Source still had to be parsed, as a stream-based Source does, Saxon parsed it with that Configuration, bypassing the protection applied to the other body types. Such a body arises, for example, after a route converts the message with convertBodyTo(Source.class), or when a component or processor earlier in the route sets the body to a stream-based Source. A DOCTYPE with an external subset, or an external entity, declared in that body was therefore resolved and expanded into the document the expression was evaluated against. An external sender whose XML reaches an XQuery expression or an xquery endpoint in that form could read files readable by the Camel process and cause the process to issue requests to hosts the document names. No non-default option is required, since the default Configuration is used whenever the route does not supply one of its own.
Users are recommended to upgrade to version 4.23.0, which fixes the issue. If users are on the 4.22.x releases stream, then they are suggested to upgrade to 4.22.2. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.5. The 4.14.x releases stream and earlier, as well as the 4.15.x to 4.17.x and 4.19.x to 4.21.x release lines, reached end of life before this issue was resolved and will not receive a fix, so deployments on them must move to a supported release. For deployments that cannot upgrade immediately, do not evaluate XQuery over a message body that is already a javax.xml.transform.Source when that body carries XML from an untrusted sender, or set the configuration option of the xquery endpoint or language to a Saxon Configuration whose parse options refuse a DOCTYPE declaration and disable external entities and external DTD loading, which is what the fixed releases now apply by default.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.6% within 30 daysSource: FIRST EPSS. FIRST's exploitation probability, not an EchelonGraph model.
- 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days 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; Attend at high (mission-essential systems).
Users are recommended to upgrade to version 4.23.0, which fixes the issue (from the CVE record's solution, Apache Software Foundation). Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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; 60 days if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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