A flaw during verification of certain S/MIME signatures causes emails to be shown in Thunderbird as having a valid digital signature, even i
A flaw during verification of certain S/MIME signatures causes emails to be shown in Thunderbird as having a valid digital signature, even if the shown message contents aren't covered by the signature. The flaw allows an attacker to reuse a valid S/MIME signature to craft an email message with arbitrary content. This vulnerability affects Thunderbird < 60.5.1.
- Published
- Apr 26, 2019
- Updated
- Jun 16, 2026
- EPSS
- 1.7% · 76th percentile
- CWE
- CWE-347
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
22
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 1.7%
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| mozilla | thunderbird | cpe:2.3:a:mozilla:thunderbird |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- mozilla thunderbirdbefore 60.5.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.
Mozilla Thunderbird
- unspecified and later · before 60.5.1affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | thunderbird | before 1:60.5.1-1 | 1:60.5.1-1 |
| Debian:8 | thunderbird | before 1:60.5.1-1~deb8u1 | 1:60.5.1-1~deb8u1 |
| Debian:9 | thunderbird | before 1:60.5.1-1~deb9u1 | 1:60.5.1-1~deb9u1 |
| openSUSE:Leap 15.0 | MozillaThunderbird | before 60.6.1-lp150.3.37.1 | 60.6.1-lp150.3.37.1 |
| Red Hat:enterprise_linux:6::client | thunderbird | before 0:60.6.1-1.el6_10 | 0:60.6.1-1.el6_10 |
| Red Hat:enterprise_linux:6::client | thunderbird-debuginfo | before 0:60.6.1-1.el6_10 | 0:60.6.1-1.el6_10 |
| Red Hat:enterprise_linux:7::client | thunderbird | before 0:60.6.1-1.el7_6 | 0:60.6.1-1.el7_6 |
| Red Hat:enterprise_linux:7::client | thunderbird-debuginfo | before 0:60.6.1-1.el7_6 | 0:60.6.1-1.el7_6 |
| Red Hat:enterprise_linux:8::appstream | thunderbird | before 0:60.6.1-1.el8 | 0:60.6.1-1.el8 |
| Red Hat:enterprise_linux:8::appstream | thunderbird-debuginfo | before 0:60.6.1-1.el8 | 0:60.6.1-1.el8 |
| Red Hat:enterprise_linux:8::appstream | thunderbird-debugsource | before 0:60.6.1-1.el8 | 0:60.6.1-1.el8 |
| SUSE:Linux Enterprise Workstation Extension 15 | MozillaThunderbird | before 60.5.1-3.24.1 | 60.5.1-3.24.1 |
| SUSE:Linux Enterprise Workstation Extension 15 | MozillaThunderbird | before 60.6.1-3.28.1 | 60.6.1-3.28.1 |
| SUSE:Package Hub 12 | MozillaThunderbird | before 60.5.1-79.1 | 60.5.1-79.1 |
Same product
mozilla: all recordsOther highest-scoring records for the same primary product.
- CVE-2019-11705A flaw in Thunderbird's implementation of iCal causes a stack buffer overflow in icalrecur_add_bydayrules when processing certain email mess42Plan
- CVE-2019-11704A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in icalmemory_strdup_and_dequote when processing certain email 42Plan
- CVE-2019-11703A flaw in Thunderbird's implementation of iCal causes a heap buffer overflow in parser_get_next_char when processing certain email messages,42Plan
- CVE-2015-2740Buffer overflow in the nsXMLHttpRequest::AppendToResponseText function in Mozilla Firefox before 39.0, Firefox ESR 31.x before 31.8 and 38.x42Plan
- CVE-2013-5603Use-after-free vulnerability in the nsContentUtils::ContentIsHostIncludingDescendantOf function in Mozilla Firefox before 25.0, Firefox ESR 42Plan
- CVE-2013-1719Multiple unspecified vulnerabilities in the browser engine in Mozilla Firefox before 24.0, Thunderbird before 24.0, and SeaMonkey before 2.242Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:thunderbird | 1:60.5.1-1 · Debian:12 | Package registry (OSV) |
| opensuse:MozillaThunderbird | 60.6.1-lp150.3.37.1 · openSUSE:Leap 15.0 | Package registry (OSV) |
| red hat:thunderbird | 0:60.6.1-1.el6_10 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:thunderbird-debuginfo | 0:60.6.1-1.el6_10 · Red Hat:enterprise_linux:6::client | Package registry (OSV) |
| red hat:thunderbird-debugsource | 0:60.6.1-1.el8 · Red Hat:enterprise_linux:8::appstream | Package registry (OSV) |
| suse:MozillaThunderbird | 60.5.1-3.24.1 · SUSE:Linux Enterprise Workstation Extension 15 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- low · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-347 · Improper Verification of Cryptographic SignatureCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
nvd-primary
Root cause
The verifier takes the algorithm to verify with from the token’s own header. Untrusted data ends up deciding its own verification rule.
The bug in code
The whole CWE-347 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
const claims = jwt.verify(token, publicKey);Fixed
const claims = jwt.verify(token, publicKey, { algorithms: ["RS256"], issuer: "https://id.example.com", audience: "portal",});Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/RUB-NDS/Johnny-You-Are-Fired
- github.com/RUB-NDS/Johnny-You-Are-Fired/blob/master/paper/johnny-fired.pdf
- bugzilla.mozilla.org/show_bug.cgi?id=1507218
- lists.opensuse.org/opensuse-security-announce/2019-04/msg00043.html
- packetstormsecurity.com/files/152703/Johnny-You-Are-Fired.html
- seclists.org/fulldisclosure/2019/Apr/38
- www.openwall.com/lists/oss-security/2019/04/30/4
- access.redhat.com/errata/RHSA-2019:1144
- www.mozilla.org/security/advisories/mfsa2019-06/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.